Orders of magnitude (length)

Overview

Detailed list

Subatomic scale

Atomic to cellular scale

Cellular to human scale

Human to astronomical scale

Astronomical scale

Less than 1 zeptometre

• 1.6 × 10⁻¹¹ yoctometres – the Planck length.
• 1 ym – 1 yoctometre, the smallest named subdivision of the metre in the SI base unit of length, one septillionth of a metre
• 2 ym – the effective cross-section radius of 1 MeV neutrinos as measured by Clyde Cowan and Frederick Reines

  1 zeptometre

• 2 zm – the upper bound for the width of a cosmic string in string theory.
• 2 zm – radius of effective cross section for a 20 GeV neutrino scattering off a nucleon
• 7 zm – radius of effective cross section for a 250 GeV neutrino scattering off a nucleon

  10 zeptometres

100 zeptometres

• 177 zm – de Broglie wavelength of protons at the Large Hadron Collider

  1 attometre

• 1 am – sensitivity of the LIGO detector for gravitational waves
• 1 am – upper limit for the size of quarks and electrons

  10 attometres

• 10 am – range of the weak force

  100 attometres

• 100 am – all lengths shorter than this distance are not confirmed in terms of size
• 850 am – approximate proton radius

  1 femtometre

• 1 fm – diameter of a neutron, approximate range-limit of the color force carried between quarks by gluons
• 1.5 fm – diameter of the scattering cross section of an 11 MeV proton with a target proton
• 1.75 fm – the effective charge diameter of a proton
• 2.81794 fm – classical electron radius
• 3 fm – approximate range-limit of the nuclear binding force mediated by mesons
• 7 fm – the radius of the effective scattering cross section for a gold nucleus scattering a 6 MeV alpha particle over 140 degrees

  10 femtometres

• 1.75 to 15 fm – Diameter range of the atomic nucleus

  100 femtometres

• 570 fm – typical distance from the atomic nucleus of the two innermost electrons in the uranium atom, the heaviest naturally-occurring atom

  1 picometre

• 1 pm – distance between atomic nuclei in a white dwarf
• 1 pm – reference value of particle displacement in acoustics
• 2.4 pm – The Compton wavelength of the electron
• 5 pm – shorter X-ray wavelengths

  10 picometres

• 25 pm – approximate radius of a helium atom, the smallest neutral atom
• 50 pm – radius of a hydrogen atom
• 50 pm – bohr radius: approximate radius of a hydrogen atom
• ~50 pm – best resolution of a high-resolution transmission electron microscope
• 60 pm – radius of a carbon atom
• 93 pm – length of a diatomic carbon molecule

  100 picometres

• 100 pm – 1 ångström
• 100 pm – covalent radius of sulfur atom
• 120 pm – van der Waals radius of a neutral hydrogen atom
• 120 pm – radius of a gold atom
• 126 pm – covalent radius of ruthenium atom
• 135 pm – covalent radius of technetium atom
• 150 pm – Length of a typical covalent bond
• 153 pm – covalent radius of silver atom
• 155 pm – covalent radius of zirconium atom
• 175 pm – covalent radius of thulium atom
• 200 pm – highest resolution of a typical electron microscope
• 225 pm – covalent radius of caesium atom
• 280 pm – Average size of the water molecule
• 298 pm – radius of a caesium atom, calculated to be the largest atomic radius
• 340 pm – thickness of single layer graphene
• 356.68 pm – width of diamond unit cell
• 403 pm – width of lithium fluoride unit cell
• 500 pm – Width of protein α helix
• 543 pm – silicon lattice spacing
• 560 pm – width of sodium chloride unit cell
• 700 pm – width of glucose molecule
• 780 pm – mean width of quartz unit cell
• 820 pm – mean width of ice unit cell
• 900 pm – mean width of coesite unit cell

  1 nanometre

• 1 nm – length of a buckyball
• 1 nm – diameter of a carbon nanotube
• 1 nm – roughly the length of a sucrose molecule, calculated by Albert Einstein
• 2.3 nm – length of a phospholipid
• 2.3 nm – smallest gate oxide thickness in microprocessors
• 3 nm – width of a DNA helix
• 3 nm – flying height of the head of a hard disk
• 3 nm – as of 2019, the average half-pitch of a memory cell expected to be manufactured circa 2022
• 3.4 nm – length of a DNA turn
• 3.8 nm – size of an albumin molecule
• 5 nm – size of the gate length of a 16 nm processor
• 5 nm – as of 2018, the average half-pitch of a memory cell expected to be manufactured circa 2019-2020
• 6 nm – length of a phospholipid bilayer
• 6-10 nm – thickness of cell membrane
• 6.8 nm – width of a haemoglobin molecule
• 7 nm – the average half-pitch of a memory cell manufactured circa 2018
• 10 nm – Thickness of cell wall in Gram-negative bacteria

  10 nanometres

• 10 nm – the average length of a nanowire
• 10 nm – lower size of tobacco smoke
• 10 nm – the average half-pitch of a memory cell manufactured circa 2016–2017
• 13 nm – the length of the wavelength that is used for EUV lithography
• 14 nm – Length of a porcine circovirus
• 14 nm – the average half-pitch of a memory cell manufactured circa 2013
• 15 nm – Length of an antibody
• 18 nm – diameter of tobacco mosaic virus
• 20 nm – Length of a nanobe, could be one of the smallest forms of life
• 20 nm to 80 nm – thickness of cell wall in Gram-positive bacteria
• 20 nm – thickness of bacterial flagellum
• 22 nm – the average half-pitch of a memory cell manufactured circa 2011-2012
• 22 nm – Smallest feature size of production microprocessors in September 2009
• 30 nm – lower size of cooking oil smoke
• 32 nm – the average half-pitch of a memory cell manufactured circa 2009–2010
• 40 nm – extreme ultraviolet wavelength
• 45 nm – the average half-pitch of a memory cell manufactured circa 2007–2008
• 50 nm – upper size for airborne virus particles
• 50 nm – flying height of the head of a hard disk
• 65 nm – the average half-pitch of a memory cell manufactured circa 2005–2006
• 58 nm – height of a T7 bacteriophage
• 90 nm – Human immunodeficiency virus
• 90 nm – the average half-pitch of a memory cell manufactured circa 2002–2003
• 100 nm – Length of a mesoporous silica nanoparticle

  100 nanometres

• 100 nm – greatest particle size that can fit through a surgical mask
• 100 nm – 90% of particles in wood smoke are smaller than this.
• 120 nm – greatest particle size that can fit through a ULPA filter
• 120 nm – diameter of a human immunodeficiency virus
• 120 nm – approximate diameter of SARS-CoV-2, the virus that causes COVID-19
• 125 nm – standard depth of pits on compact discs
• 180 nm – typical length of the rabies virus
• 200 nm – typical size of a Mycoplasma bacterium, among the smallest bacteria
• 300–400 nm – near ultraviolet wavelength
• 300 nm – greatest particle size that can fit through a HEPA filter
• 400–420 nm – wavelength of violet light
• 420–440 nm – wavelength of indigo light
• 440–500 nm – wavelength of blue light
• 500–520 nm – wavelength of cyan light
• 520–565 nm – wavelength of green light
• 565–590 nm – wavelength of yellow light
• 590–625 nm – wavelength of orange light
• 625–700 nm – wavelength of red light
• 700–1.4 μm – wavelength of near-infrared radiation

  1 micrometre

• ~0.7–300 μm – wavelength of infrared radiation
• 1 μm – the side of square of area 10⁻¹² m²
• 1 μm – edge of cube of volume 10⁻¹⁸ m³
• 1–10 μm – diameter of a typical bacterium
• 1 μm – length of a lysosome
• 1-2 μm – anthrax spore
• 2 μm – length of an average E. coli bacteria
• 3–4 μm – size of a typical yeast cell
• 5 μm – length of a typical human spermatozoon's head
• 6 μm – thickness of the tape in a 120-minute compact cassette
• 7 μm – diameter of the nucleus of a typical eukaryotic cell
• about 7 μm – diameter of human red blood cells
• 3–8 μm – width of strand of spider web silk
• 5-10 μm – width of a chloroplast
• 8-11 μm – size of a ground-level fog or mist droplet

  10 micrometres

• 10 μm – width of cotton fibre
• 10 μm – transistor width of the Intel 4004, the world's first commercial microprocessor
• 10 μm – mean longest dimension of a human red blood cell
• 5–20 μm – dust mite excreta
• 10.6 μm – wavelength of light emitted by a carbon dioxide laser
• 15 μm – width of silk fibre
• 17 μm – minimum width of a strand of human hair
• 17.6 μm – one twip, a unit of length in typography
• 10 to 55 μm – width of wool fibre
• 25.4 μm – 1/1000 inch, commonly referred to as 1 mil in the U.S. and 1 thou in the UK
• 30 μm – length of a human skin cell
• 50 μm – typical length of Euglena gracilis, a flagellate protist
• 50 μm – typical length of a human liver cell, an average-sized body cell
• 50 μm – length of a silt particle
• 60 μm – length of a sperm cell
• 70 to 180 μm – thickness of paper

  100 micrometres

• 100 μm – 1/10 of a millimetre
• 100 μm – 0.00394 inches
• 100 μm – smallest distance that can be seen with the naked eye
• 100 μm – average diameter of a strand of human hair
• 100 μm – thickness of a coat of paint
• 100 μm – length of a dust particle
• 120 μm – the geometric mean of the Planck length and the diameter of the observable universe:
• 120 μm – diameter of a human ovum
• 170 μm – length of the largest sperm cell in nature, belonging to the Drosophila bifurca fruit fly
• 181 μm – maximum width of a strand of human hair
• 100–400 μm – length of Demodex mites living in human hair follicles
• 200 μm – typical length of Paramecium caudatum, a ciliate protist
• 200 μm - nominal width of the smallest commonly available mechanical pencil lead
• 250–300 μm – length of a dust mite
• 340 μm – length of a single pixel on a 17-inch monitor with a resolution of 1024×768
• 500 μm – typical length of Amoeba proteus, an amoeboid protist
• 500 μm – average length of a grain of sand
• 500 μm – average length of a grain of salt
• 500 μm – average length of a grain of sugar
• 560 μm – thickness of the central area of a human cornea
• 750 μm – diameter of a Thiomargarita namibiensis, the largest bacteria known
• 760 μm – thickness of an identification card

  1 millimetre

• 1.0 mm – 1/1000 of a metre
• 1.0 mm – 0.03937 inches or 5/127
• 1.0 mm – side of square of area 1 mm²
• 1.0 mm – diameter of a pinhead
• 1.5 mm – length of average flea
• 2.54 mm – distance between pins on old dual in-line package electronic components
• 5 mm – length of an average red ant
• 5 mm – diameter of an average grain of rice
• 5.56×45mm NATO – standard ammunition size
• 6 mm – approximate width of a pencil
• 7 mm – length of a Paedophryne amauensis, the smallest known vertebrate
• 7.1 mm – length of a sunflower seed
• 7.62×51mm NATO – common military ammunition size
• 8 mm – width of old-format home movie film
• 8 mm – length of a Paedocypris progenetica, the smallest known fish

  1 centimetre

• 1 cm – 10 millimetres
• 1 cm – 0.39 inches
• 1 cm – edge of square of area 1 cm²
• 1 cm – edge of cube of volume 1 mL
• 1 cm – length of a coffee bean
• 1 cm – approximate width of average fingernail
• 1.2 cm – length of a bee
• 1.2 cm – diameter of a die
• 1.5 cm – length of a very large mosquito
• 1.6 cm – length of a Jaragua Sphaero, a very small reptile
• 1.7 cm – length of a Thorius arboreus, the smallest salamander
• 2 cm – approximate width of an adult human finger
• 2.54 cm – 1 inch
• 3.1 cm – 1 attoparsec
• 3.4 cm – length of a quail egg
• 3.5 cm – width of film commonly used in motion pictures and still photography
• 4.3 cm – minimum diameter of a golf ball
• 5 cm – usual diameter of a chicken egg
• 5 cm – height of a hummingbird, the smallest known bird
• 5.5 × 5.5 × 5.5 cm – dimensions of a 3x3x3 Rubik's Cube
• 6.1 cm – average height of an apple
• 7.3–7.5 cm – diameter of a baseball
• 8.6 cm × 5.4 cm – dimensions of a standard credit card
• 9 cm – length of a speckled padloper, the smallest known turtle

  1 decimetre

Conversions

• 1 decimetre, a term not in common use
• 100 millimetres
• 3.9 inches
• a side of a square of area 0.01 m²
• the edge of a cube with a volume of m³

  Wavelengths

• 10 cm = 1.0 dm – wavelength of the highest UHF radio frequency, 3 GHz
• 12 cm = 1.2 dm – wavelength of the 2.45 GHz ISM radio band
• 21 cm = 2.1 dm – wavelength of the 1.4 GHz hydrogen emission line, a hyperfine transition of the hydrogen atom
• 100 cm = 10 dm – wavelength of the lowest UHF radio frequency, 300 MHz

  Human-defined scales and structures

• 10.16 cm = 1.016 dm – 1 hand used in measuring height of horses
• 12 cm = 1.2 dm – diameter of a compact disc
• 15 cm = 1.5 dm – length of a Bic pen with cap on
• 22 cm = 2.2 dm – diameter of a typical association football
• 30 cm = 3 dm – typical school-use ruler length
• 30.48 cm = 3.048 dm – 1 foot
• 60 cm = 6 dm – standard depth of a domestic kitchen worktop in Europe
• 90 cm = 9 dm – average length of a rapier, a fencing sword
• 91.44 cm = 9.144 dm – one yard

  Nature

• 10 cm = 1 dm – diameter of the human cervix upon entering the second stage of
• 11 cm = 1.1 dm – diameter of an average potato in the US
• 15 cm = 1.5 dm – approximate size of largest beetle species
• 19 cm = 1.9 dm – length of a banana
• 26.3 cm = 2.6 dm – length of average male human foot
• 29.98 cm = 2.998 dm – distance light travels in one nanosecond
• 31 cm = 3.1 dm – wingspan of largest butterfly species Ornithoptera alexandrae
• 46 cm = 4.6 dm – length of an average domestic cat
• 50 to 65 cm = 5–6.5 dm – a coati's tail
• 66 cm = 6.6 dm – length of the longest pine cones

  Astronomical

• 84 cm = 8.4 dm – approximate diameter of 2008 TS26, a meteoroid

  1 metre

Conversions

• 10 decimetres
• 100 centimetres
• 1,000 millimetres
• 39.37 inches
• 3.28 feet
• side of square with area 1 m²
• edge of cube with surface area 6 m² and volume 1 m³
• radius of circle with area 3.14 m²
• radius of sphere with surface area 12.56 m² and volume 4.19 m³

  Human-defined scales and structures

• 1 m – approximate height of the top part of a doorknob on a door
• 1 m – diameter of a very large beach ball
• 1.435 m – standard gauge of railway track used by about 60% of railways in the world = 4 ft 8½ in
• 2.5 m – distance from the floor to the ceiling in an average residential house
• 2.7 m – length of the Starr Bumble Bee II, the smallest plane
• 2.77–3.44 m – wavelength of the broadcast radio FM band 87–108 MHz
• 3.05 m – the length of an old Mini
• 8.38 m – the length of a London Bus

  Sports

• 2.44 m – height of an association football goal
• 2.45 m – highest high jump by a human being
• 3.05 m – height of the basket in basketball
• 8.95 m – longest long jump by a human being

  Nature

• 1 m – height of Homo floresiensis
• 1.15 m – a pizote
• 1.37 m – average height of an Andamanese person
• 1.63 m – - height of average US female human
• 1.75 m – - height of average US male human
• 2.5 m – height of a sunflower
• 2.72 m – - tallest known human being
• 3.63 m – the record wingspan for living birds
• 5 m – length of an elephant
• 5.2 m – height of a giraffe
• 5.5 m – height of a Baluchitherium, the largest land mammal ever lived
• 7 m – wingspan of Argentavis, the largest flying bird known
• 7.5 m – approximate length of the human gastrointestinal tract

  Astronomical

• 3–6 m – approximate diameter of, a meteoroid
• 4.1 m – diameter of 2008 TC3, a small asteroid that flew into the Earth's atmosphere on October 7, 2008.

  1 decametre

Conversions

• 10 metres
• 100 decimetres
• 1,000 centimetres
• 10,000 millimetres
• 32.8 feet
• side of square with area 100 m²

  Human-defined scales and structures

• 10 metres – wavelength of the highest shortwave radio frequency, 30 MHz
• 23 metres – height of the obelisk of the Place de la Concorde, Paris, France
• 25 metres – wavelength of the broadcast radio shortwave band at 12 MHz
• 29 metres – height of the lighthouse at Savudrija, Slovenia
• 31 metres – wavelength of the broadcast radio shortwave band at 9.7 MHz
• 34 metres – height of the Split Point Lighthouse in Aireys Inlet, Victoria, Australia
• 40 metres – average depth beneath the seabed of the Channel tunnel
• 49 metres – wavelength of the broadcast radio shortwave band at 6.1 MHz
• 50 metres – length of a road train
• 55 metres – height of the Leaning Tower of Pisa
• 62.5 metres – height of Pyramid of Djoser
• 64 metres – wingspan of a Boeing 747-400
• 69 metres – wingspan of an Antonov An-124 Ruslan
• 70 metres – length of the Bayeux Tapestry
• 70 metres – width of a typical association football field
• 77 metres – wingspan of a Boeing 747-8
• 88.4 metres – wingspan of the Antonov An-225 Mriya transport aircraft
• 93 metres – height of the Statue of Liberty
• 96 metres – height of Big Ben
• 100 metres – wavelength of the lowest shortwave radio frequency, 3 MHz

  Sports

• 11 metres – approximate width of a doubles tennis court
• 15 metres – width of a standard FIBA basketball court
• 15.24 metres – width of an NBA basketball court
• 18.44 metres – distance between the front of the pitcher's rubber and the rear point of home plate on a baseball field
• 20 metres – length of cricket pitch
• 27.43 metres – distance between bases on a baseball field
• 28 metres – length of a standard FIBA basketball court
• 28.65 metres – length of an NBA basketball court
• 49 metres – width of an American football field
• 59.436 metres – width of a Canadian football field
• 70 metres – typical width of soccer field
• 91 metres – length of American football field
• 105 metres – length of football pitch

  Nature

• 10 metres – average length of human digestive tract
• 12 metres – length of a whale shark, largest living fish
• 12 metres – wingspan of a Quetzalcoatlus, a pterosaur
• 13 metres – length of a giant squid and colossal squid, the largest living invertebrates
• 15 metres – approximate distance the tropical circles of latitude are moving towards the equator and the polar circles are moving towards the poles each year due to a natural, gradual decrease in the Earth's axial tilt
• 18 metres – height of a Sauroposeidon, the tallest known dinosaur
• 20 metres – length of a Leedsichthys, the largest known fish ever lived
• 21 metres – height of High Force waterfall in England
• 33 metres – length of a blue whale, the largest animal on earth, living or extinct, in terms of mass
• 35 metres – length of a Supersaurus, the longest known dinosaur and longest vertebrate
• 52 metres – height of Niagara Falls
• 55 metres – length of a bootlace worm, the longest known animal
• 83 metres – height of a Western hemlock

  Astronomical

• 30 metres – diameter of, a rapidly spinning meteoroid
• 32 metres – approximate diameter of 2008 HJ, a small meteoroid

  1 hectometre

Conversions

• 328 feet
• one side of a 1 hectare square
• a fifth of a modern li, a Chinese unit of measurement
• the approximate distance travelled by light in 300 nanoseconds

  Human-defined scales and structures

• 100 metres – wavelength of the highest medium wave radio frequency, 3 MHz
• 100 metres – spacing of location marker posts on British motorways
• 138.8 metres – height of the Great Pyramid of Giza
• 139 metres – height of the world's tallest roller coaster, Kingda Ka
• 187 metres – shortest wavelength of the broadcast radio AM band, 1600 kHz
• 202 metres – length of the Széchenyi Chain Bridge connecting Buda and Pest
• 318 metres – height of The New York Times Building
• 318.9 metres – height of the Chrysler Building
• 320.75 metres – height of the Eiffel Tower
• 328 metres – height of Auckland's Sky Tower, the tallest free-standing structure in the Southern Hemisphere
• 341 metres – height of the world's tallest bridge, the Millau Viaduct
• 390 metres – height of the Empire State Building
• 400–800 metres – approximate heights of the world's tallest skyscrapers of the past 80 years
• 458 metres – length of the Knock Nevis, the world's largest supertanker
• 553.33 metres – height of the CN Tower
• 555 metres – longest wavelength of the broadcast radio AM band, 540 kHz
• 630 metres – height of the KVLY-TV mast, second tallest structure in the world
• 646 metres – height of the Warsaw radio mast, the world's tallest structure until its collapse in 1991
• 828 metres – height of Burj Khalifa, world's tallest structure on 17 January 2009
• 1,000 metres – wavelength of the lowest mediumwave radio frequency, 300 kHz

  Sports

• 100 metres – the distance a very fast human being can run in about 10 seconds
• 100.584 metres – length of a Canadian football field between the goal lines
• 91.5 metres – 137 metres – length of a soccer field
• 105 metres – length of a typical football field
• 109.73 metres – total length of an American football field
• 110 – 150 metres-the width of an Australian football field
• 135 – 185 metres the length of an Australian football field
• 137.16 metres – total length of a Canadian football field, including the end zones

  Nature

• 115.5 metres – height of the world's tallest tree in 2007, the Hyperion sequoia
• 310 metres – maximum depth of Lake Geneva
• 340 metres – distance sound travels in air at sea level in one second; see Speed of sound
• 979 metres – height of the Salto Angel, the world's highest free-falling waterfall
• 1500 metres – distance sound travels in water in one second;

  Astronomical

• 270 metres – length of 99942 Apophis
• 535 metres – length of 25143 Itokawa, a small asteroid visited by a spacecraft

  1 kilometre

Conversions

• 1,000 metres
• 0.621371 miles
• 1,093.61 yards
• 3,280.84 feet
• 39,370.1 inches
• 100,000 centimetres
• 1,000,000 millimetres
• Side of a square of area 1 km²
• Radius of a circle of area π km²

  Human-defined scales and structures

• 1 km – wavelength of the highest long wave radio frequency, 300 kHz
• 1.280 km – span of the Golden Gate Bridge
• 1.609 km – 1 mile
• 1.852 km – 1 nautical mile, equal to 1 arc minute of latitude at the surface of the Earth
• 1.991 km – span of the Akashi Kaikyō Bridge
• 2.309 km – axial length of the Three Gorges Dam, the largest dam in the world
• 3.991 km – length of the Akashi Kaikyō Bridge, longest suspension bridge in the world
• 5.072 km – height of Tanggula Mountain Pass, below highest peak in the Tanggula Mountains, highest railway pass in the world
• 5.727 km – height of Cerro Aucanquilcha, highest road in the world, located in Chile
• 98 airports have paved runways from 4 km to 5.5 km in length.
• 8 km – length of Palm Jebel Ali, an artificial island built off the coast of Dubai
• 9.8 km – length of The World, an artificial archipelago that is also built off the coast of Dubai, whose islands resemble a world map

  Geographical

• 1.637 km – deepest dive of Lake Baikal in Russia, the world's largest fresh water lake
• 2.228 km – height of Mount Kosciuszko, highest point on mainland Australia
• Most of Manhattan is from 3 to 4 km wide.
• 4.810 km – height of Mont Blanc, highest peak in the Alps
• 4.884 km – height of Carstensz Pyramid, highest peak in Oceania
• 4.892 km – height of Mount Vinson, highest peak in Antarctica
• 5.610 km – height of Mount Damavand, highest peak in Iran
• 5.642 km – height of Mount Elbrus, highest peak in Europe
• 5.895 km – height of Mount Kilimanjaro, highest peak in Africa
• 6.081 km – height of Mount Logan, highest peak in Canada
• 6.194 km – height of Denali, highest peak in North America
• 6.959 km – height of Aconcagua, highest peak in South America
• 7.5 km – depth of Cayman Trench, deepest point in the Caribbean Sea
• 8.848 km – height of Mount Everest, highest peak on Earth, on the border between Nepal and China

  Astronomical

• 1 km – diameter of 1620 Geographos
• 1 km – very approximate size of the smallest known moons of Jupiter
• 1.4 km – diameter of Dactyl, the first confirmed asteroid moon
• 4.8 km – diameter of 5535 Annefrank, an inner belt asteroid
• 5 km – diameter of 3753 Cruithne
• 5 km – length of PSR B1257+12
• 8 km – diameter of Themisto, one of Jupiter's moons
• 8 km – diameter of the Vela Pulsar
• 8.6 km – diameter of Callirrhoe, also known as Jupiter XVII
• 9.737 km – length of PSR B1919+21

  10 kilometres

Conversions

• 10,000 metres
• 6.2 miles
• 1 mil , now standardized as 10 km:
• *1 mil, the unit of measure commonly used in Norway and Sweden used to be 11,295 m in Norway and 10,688 m in Sweden.
• farsang, unit of measure commonly used in Iran and Turkey

  Sports

• 42.195 km – length of the marathon

  Human-defined scales and structures

• 18 km – cruising altitude of Concorde
• 27 km – circumference of the Large Hadron Collider, the largest and highest energy particle accelerator
• 34.668 km – highest manned balloon flight
• 38.422 km – length of the Second Lake Pontchartrain Causeway in Louisiana, US
• 39 km – undersea portion of the Channel tunnel
• 53.9 km – length of the Seikan Tunnel,, the longest rail tunnel in the world
• 77 km – Rough total length of the Panama Canal

  Geographical

• 10 km – height of Mauna Kea in Hawaii, measured from its base on the ocean floor
• 11 km – deepest known point of the ocean, Challenger Deep in the Mariana Trench
• 11 km – average height of the troposphere
• 14 km – width of the Gibraltar strait
• 21 km – length of Manhattan
• 23 km – depth of the largest earthquake ever recorded in the United Kingdom, in 1931 at the Dogger Bank of the North Sea
• 34 km – narrowest width of the English Channel at the Strait of Dover
• 50 km – approximate height of the stratosphere
• 90 km – width of the Bering Strait

  Astronomical

• 10 km – diameter of the most massive neutron stars
• 13 km – mean diameter of Deimos, the smaller moon of Mars
• 20 km – diameter of the least massive neutron stars
• 20 km – diameter of Leda, one of Jupiter's moons
• 20 km – diameter of Pan, one of Saturn's moons
• 22 km – diameter of Phobos, the larger moon of Mars
• 27 km – height of Olympus Mons above the Mars reference level, the highest known mountain of the Solar System
• 43 km – diameter difference of Earth's equatorial bulge
• 66 km – diameter of Naiad, the innermost of Neptune's moons

  100 kilometres

Conversions

Human-defined scales and structures

• 100 km – the Karman line: the official boundary of outer space
• 105 km – distance from Giridih to Bokaro
• 109 km – length of High Speed 1 between London and the Channel Tunnel
• 130 km – range of a Scud-A missile
• 163 km – length of the Suez Canal
• 164 km – length of the Danyang–Kunshan Grand Bridge
• 213 km – length of Paris Métro
• 217 km – length of the Grand Union Canal
• 223 km – length of the Madrid Metro
• 300 km – range of a Scud-B missile
• 386 km – altitude of the International Space Station
• 408 km – length of the London Underground
• 460 km – distance from London to Paris
• 470 km – distance from Dublin to London as the crow flies
• 600 km – range of a Scud-C missile
• 600 km – height above ground of the Hubble Space Telescope
• 804.67 km – distance of the Indy 500 automobile race

  Geographical

• 111 km – distance covered by one degree of latitude on Earth's surface
• 180 km – distance between Mumbai and Nashik
• 203 km – length of Sognefjorden, the third largest fjord in the world
• 220 km – distance between Pune and Nashik
• 240 km – widest width of the English Channel
• 430 km – length of the Pyrenees
• 500 km – widest width of Sweden from east to west
• 550 km – distance from San Francisco to Los Angeles as the crow flies
• 560 km – distance of Bordeaux–Paris, formerly the longest one-day professional cycling race
• 590 km – length of land boundary between Finland and Sweden
• 724 km – length of the Om River
• 871 km – distance from Sydney to Melbourne
• 897 km – length of the River Douro
• 900 km – distance from Berlin to Stockholm
• 956 km - distance from Washington, DC to Chicago, Illinois as the crow flies

  Astronomical

• 100 km – the altitude at which the FAI defines spaceflight to begin
• 167 km – diameter of Amalthea, one of Jupiter's inner moons
• 200 km – width of Valles Marineris
• 220 km – diameter of Phoebe, the largest of Saturn's outer moons
• 300 km – the approximate distance travelled by light in one millisecond
• 340 km – diameter of Nereid, the third largest moon of Neptune
• 350 km – lower bound of Low Earth orbit
• 420 km – diameter of Proteus, the second largest moon of Neptune
• 468 km – diameter of the asteroid 4 Vesta
• 472 km – diameter of Miranda, one of Uranus' major moons
• 974.6 km – greatest diameter of 1 Ceres, the largest solar system asteroid

  1 megametre

Conversions

• 1 E+6 m
• approximately 621.37 miles
• Side of square with area 1,000,000 km²

  Human-defined scales and structures

• 2.100 Mm – Length of proposed gas pipeline from Iran to India via Pakistan
• 2.100 Mm – Distance from Casablanca to Rome
• 2.288 Mm – Length of the official Alaska Highway when it was built in the 1940s
• 3.069 Mm – Length of Interstate 95
• 3.846 Mm – Length of U.S. Route 1
• 5.000 Mm – Width of the United States
• 5.007 Mm – Estimated length of Interstate 90
• 5.614 Mm – Length of the Australian Dingo Fence
• 6.4 Mm – Length of the Great Wall of China
• 7.821 Mm – Length of the Trans-Canada Highway, the world's longest national highway
• 8.836 Mm – Road distance between Prudhoe Bay, Alaska, and Key West, Florida, the endpoints of the U.S. road network
• 8.852 Mm – Aggregate length of the Great Wall of China, including trenches, hills and rivers
• 9.259 Mm – Length of the Trans-Siberian railway

  Sports

• The Munda Biddi Trail in WA, Australia is over 1000 km long - the world's longest off-road cycle trail
• 1.200 Mm – the length of the Paris–Brest–Paris bicycling event
• Several endurance auto races are, or were, run for 1,000 km:
• *Bathurst 1000
• *1000 km Brands Hatch
• *1000 km Buenos Aires
• *1000 km Donington
• *1000 km Monza
• *1000 km Nürburgring
• *1000 km Silverstone
• *1000 km Spa
• *1000 km Suzuka
• *1000 km Zeltweg

  Geographical

• 1.010 Mm – Distance from San Diego to El Paso as the crow flies
• 2.000 Mm – Distance from Beijing to Hong Kong as the crow flies
• 2.800 Mm – Narrowest width of Atlantic Ocean
• 2.850 Mm – Length of the Danube river
• 2.205 Mm – Length of Sweden's total land boundaries
• 2.515 Mm – Length of Norway's total land boundaries
• 3.690 Mm – Length of the Volga river, longest in Europe
• 4.350 Mm – Length of the Yellow River
• 4.800 Mm – Widest width of Atlantic Ocean
• 5.100 Mm – Distance from Dublin to New York as the crow flies
• 6.270 Mm – Length of the Mississippi-Missouri River system
• 6.380 Mm – Length of the Yangtze River
• 6.400 Mm – Length of the Amazon River
• 6.758 Mm – Length of the Nile system, longest on Earth
• 8.200 Mm – Distance from Dublin to San Francisco as the crow flies

  Astronomical

• 1.000 Mm – Estimated shortest axis of triaxial dwarf planet
• 1.186 Mm – Diameter of Charon, the largest moon of Pluto
• 1.280 Mm – Diameter of the trans-Neptunian object 50000 Quaoar
• 1.436 Mm – Diameter of Iapetus, one of Saturn's major moons
• 1.578 Mm – Diameter of Titania, the largest of Uranus' moons
• 1.960 Mm – Estimated longest axis of Haumea
• 2.326 Mm – Diameter of the dwarf planet Eris, the largest trans-Neptunian object found to date
• 2.376 Mm – Diameter of Pluto
• 2.707 Mm – Diameter of Triton, largest moon of Neptune
• 3.122 Mm – Diameter of Europa, the smallest Galilean satellite of Jupiter
• 3.476 Mm – Diameter of Earth's Moon
• 3.643 Mm – Diameter of Io, a moon of Jupiter
• 4.821 Mm – Diameter of Callisto, a moon of Jupiter
• 4.879 Mm – Diameter of Mercury
• 5.150 Mm – Diameter of Titan, the largest moon of Saturn
• 5.262 Mm – Diameter of Jupiter's moon Ganymede, the largest moon in the solar system
• 6.371 Mm – Radius of Earth
• 6.792 Mm – Diameter of Mars

  10 megametres

Conversions

• 6,215 miles
• side of a square of area 100,000,000 square kilometres
• radius of a circle of area 314,159,265 km²

  Human-defined scales and structures

• 11.085 Mm – Length of the Kiev-Vladivostok railway, a longer variant of the Trans-Siberian railway
• 13.300 Mm – Length of roads being rehabilitated and widened under the National Highway Development Project in India
• 39.000 Mm – Length of the SEA-ME-WE 3 optical submarine telecommunications cable, joining 39 points between Norden, Germany and Okinawa, Japan
• 67.000 Mm – Total length of National Highways in India
• 80.000 Mm – 20,000 leagues

  Geographical

• 10 Mm – Approximate altitude of the outer boundary of the exosphere
• 10.001 Mm – Length of the meridian arc from the North Pole to the Equator
• 60.000 Mm – Total length of the mid-ocean ridges

  Astronomical

• 12.000 Mm – Diameter of Sirius B, a white dwarf
• 12.104 Mm – Diameter of Venus
• 12.742 Mm – Diameter of Earth
• 12.900 Mm – Minimum distance of the meteoroid from the centre of Earth on 31 March 2004, closest on record
• 14.000 Mm – Smallest diameter of Jupiter's Great Red Spot
• 19.000 Mm – Separation between Pluto and Charon
• 34.770 Mm – Minimum distance of the asteroid 99942 Apophis on 13 April 2029 from the centre of Earth
• 35.786 Mm – Altitude of geostationary orbit
• 40.005 Mm – Polar circumference of the Earth
• 40.077 Mm – Equatorial circumference of the Earth
• 49.528 Mm – Diameter of Neptune
• 51.118 Mm – Diameter of Uranus

  100 megametres

• 102 Mm – Diameter of HD 149026 b, an unusually dense Jovian planet
• 115 Mm – Width of Saturn's Rings
• 120 Mm – Diameter of EBLM J0555-57Ab, the smallest known star
• 120 Mm – Diameter of Saturn
• 142 Mm – Diameter of Jupiter, the largest planet in the solar system
• 170 Mm – Diameter of TRAPPIST-1, a star recently discovered to have 7 planets around it
• 174 Mm – Diameter of OGLE-TR-122b
• 180 Mm – Average distance covered during life
• 196 Mm – Diameter of Proxima Centauri, a typical red dwarf
• 257 Mm – Diameter of TrES-4 b
• 272 Mm – Diameter of WASP-12b
• 299.792 Mm – One light second; the distance light travels in vacuum in one second
• 300 Mm – Diameter of WASP-79b
• 314 Mm – Diameter of CT Cha b
• 384.4 Mm – Average Earth-Moon distance
• 671 Mm – Separation between Jupiter and Europa
• 428 Mm – Diameter of GQ Lupi b, one of the largest known planets
• 986 Mm – Diameter of HD 100546 b's surrounding disk

  1 gigametre

• 1.2 Gm – Separation between Saturn and Titan
• 1.39 Gm – Diameter of Sun
• 1.5 Gm – Expected orbit from Earth of the James Webb Space Telescope
• 2.19 Gm – Closest approach of Comet Lexell to Earth, happened on 1 July 1770; closest comet approach on record
• 3 Gm – Total length of "wiring" in the human brain
• 4.2 Gm – Diameter of Algol B
• 5.0 Gm – Closest approach of Comet Halley to Earth, happened on 10 April 837
• 5.0 Gm – Size of the arms of the giant triangle shaped Michelson interferometer of the Laser Interferometer Space Antenna planned to start observations sometime in the 2030s.
• 7.9 Gm – Diameter of Gamma Orionis
• 9.0 Gm – Estimated diameter of the event horizon of Sagittarius A*, the supermassive black hole in the center of the Milky Way galaxy

  10 gigametres

• 15 Gm – Closest distance of Comet Hyakutake from Earth
• 18 Gm – One light-minute
• 24 Gm – Radius of a heliostationary orbit
• 46 Gm – Perihelion distance of Mercury
• 55 Gm – 60,000-year perigee of Mars
• 55 Gm - Radius of Rigel, a blue supergiant star
• 58 Gm – Average passing distance between Earth and Mars at the moment they overtake each other in their orbits
• 61 Gm – Diameter of Aldebaran, an orange giant star
• 70 Gm – Aphelion distance of Mercury
• 76 Gm – Neso's apocentric distance; greatest distance of a natural satellite from its parent planet

  100 gigametres

• 109 Gm Distance between Venus and the Sun
• 149.6 Gm – Distance between the Earth and the Sun - the original definition of the astronomical unit
• 180 Gm – Maximum diameter of Sagittarius A*, the supermassive black hole in the center of Milky Way galaxy
• 228 Gm – Distance between Mars and the Sun
• 570 Gm – Length of the tail of Comet Hyakutake measured by Ulysses; the actual value could be much higher
• 591 Gm – Minimum distance between the Earth and Jupiter
• 780 Gm – Distance between Jupiter and the Sun
• 947 Gm – Diameter of Antares A
• 965 Gm – Maximum distance between the Earth and Jupiter

  1 terametre

• 1.079 [|Tm] – 7.2 AU – One light-hour
• 1.4 Tm – 9.5 AU – Distance between Saturn and the Sun
• 1.83 Tm – 12.2 AU – Diameter of HR 5171 A, the largest known yellow hypergiant star although the latest research suggests it is a red hypergiant with a diameter about 2.1 Tm
• 1.5 Tm - 10 AU - Estimated diameter of VV Cephei A, a red supergiant.
• 2 Tm – 13.2 AU – Estimated diameter of VY Canis Majoris, one of the largest known stars.
• 2.9 Tm – 19.4 AU – Distance between Uranus and the Sun
• 3 Tm – 20 AU – Diameter of Stephenson 2-18, the largest known star.
• 4.4 Tm – 29.4 AU – Perihelion distance of Pluto
• 4.5 Tm – 30.1 AU – Distance between Neptune and the Sun
• 4.5 Tm – 30.1 AU – Inner radius of the Kuiper belt
• 5.7 Tm – 38.1 AU – Perihelion distance of Eris
• 7.3 Tm – 48.8 AU – Aphelion distance of Pluto
• 7.5 Tm – 50.1 AU – Outer radius of the Kuiper Belt, inner boundary of the Oort Cloud

  10 terametres

• 10 Tm – 67 AU – Diameter of a hypothetical quasi-star
• 11.1 Tm – 74.2 AU – Distance that Voyager 1 began detecting returning particles from termination shock
• 11.4 Tm – 76.2 AU – Perihelion distance of 90377 Sedna
• 12.1 Tm – 70 to 90 AU – Distance to termination shock
• 12.9 Tm – 86.3 AU – Distance to 90377 Sedna in March 2014
• 13.2 Tm – 88.6 AU – Distance to Pioneer 11 in March 2014
• 14.1 Tm – 94.3 AU – Estimated radius of the solar system
• 14.4 Tm – 96.4 AU – Distance to Eris in March 2014
• 15.1 Tm – 101 AU – Distance to heliosheath
• 16.5 Tm – 111 AU – Distance to Pioneer 10 as of March 2014
• 16.6 Tm - 111.2 AU - Distance to Voyager 2 as of May 2016
• 20.0 Tm - 135 AU - Distance to Voyager 1 as of May 2016
• 20.6 Tm – 138 AU - Distance to Voyager 1 as of late February 2017
• 21.1 Tm – 141 AU - Distance to Voyager 1 as of November 2017
• 25.9 Tm – 172 AU – One light-day
• 55.7 Tm – 371 AU – Aphelion distance of the comet Hale-Bopp

  100 terametres

• 146 Tm – 975 AU – Aphelion distance of 90377 Sedna
• 172 Tm – 1150 AU – Schwarzschild diameter of H1821+643, one of the most massive black holes known
• 181 Tm – 1210 AU – One light-week
• 653 Tm – 4367 AU – Aphelion distance of comet Hyakutake
• 757 Tm – 5059 AU – radius of the Stingray Nebula
• 777 Tm – 5180 AU – One light-month

  1 petametre

• 1.0 [|Pm] = 0.105702341 light years
• 1.9 Pm ± 0.5 Pm = 12,000 AU = 0.2 light year radius of Cat's Eye Nebula's inner core
• 4.7 Pm = 30,000 AU = half light year diameter of Bok globule Barnard 68
• 7.5 Pm – 50,000 AU – Possible outer boundary of Oort cloud
• 7.7 Pm – 52,000 AU – Aphelion distance of the Great Daylight Comet of 1910
• 9.5 Pm – 63,241.1 AU – One light year, the distance travelled by light in one year

  10 petametres

• 15 Pm – 1.59 light years – Possible outer radius of Oort cloud
• 20 Pm – 2.11 light years – maximum extent of influence of the Sun's gravitational field
• 30.9 Pm – 3.26 light years – 1 parsec
• 39.9 Pm – 4.22 light years – Distance to Proxima Centauri
• 81.3 Pm – 8.59 light years – Distance to Sirius

  100 petametres

• 110 Pm – 12 light years – Distance to Tau Ceti
• 230 Pm – 24 light years – Diameter of the Orion Nebula
• 240 Pm – 25 light years – Distance to Vega
• 260 Pm – 27 light years – Distance to Chara, a star approximately as bright as our Sun. Its faintness gives us an idea how our Sun would appear when viewed from even so close a distance as this.
• 350 Pm – 37 light years – Distance to Arcturus
• 373.1 Pm – 39.44 light years - Distance to TRAPPIST-1, a star recently discovered to have 7 planets around it
• 400 Pm – 42 light years – Distance to Capella
• 620 Pm – 65 light years – Distance to Aldebaran
• 750 Pm - 79.36 light years - Distance to Regulus
• 900 Pm - 92.73 light years - Distance to Algol

  1 exametre

• 1.2 Em – 129 light years – Diameter of Messier 13
• 1.6 Em – 172 ± 12.5 light years – Diameter of Omega Centauri
• 3.1 Em – 310 light years – Distance to Canopus according to Hipparcos
• 6.1 Em – 640 light years – Distance to Betelgeuse according to Hipparcos
• 6.2 Em – 650 light years – Distance to the Helix Nebula, located in the constellation Aquarius
• 7.3 Em – 730 light years – Distance to Rigel according to Hipparcos

  10 exametres

• 13 Em – 1,300 light years – Distance to the Orion Nebula
• 14 Em – 1,500 light years – Approximate thickness of the plane of the Milky Way galaxy at the Sun's location
• 14.2 Em – 1,520 light years – Diameter of the NGC 604
• 30.8568 Em – 3,261.6 light years – 1 kiloparsec
• 31 Em – 3,200 light years – Distance to Deneb according to Hipparcos
• 46 Em – 4,900 light years – Distance to OGLE-TR-56, the first extrasolar planet discovered using the transit method
• 47 Em – 5,000 light years – Distance to the Boomerang nebula, coldest place known
• 53 Em – 5,600 light years – Distance to the globular cluster M4 and the extrasolar planet PSR B1620-26 b within it
• 61 Em – 6,500 light years – Distance to Perseus Spiral Arm
• 71 Em – 7,500 light years – Distance to Eta Carinae

  100 exametres

• 150 Em – 16,000 light years – Diameter of the Small Magellanic Cloud, a dwarf galaxy orbiting the Milky Way
• 200 Em – 21,500 light years – Distance to OGLE-2005-BLG-390Lb, the most distant and the most Earth-like planet known
• 240 Em – 25,000 light years – Distance to the Canis Major Dwarf Galaxy
• 260 Em – 28,000 light years – Distance to the center of the Galaxy
• 830 Em – 88,000 light years – Distance to the Sagittarius Dwarf Elliptical Galaxy

  1 zettametre

• 1.7 Zm – 179,000 light years – Distance to the Large Magellanic Cloud, largest satellite galaxy of the Milky Way
• <1.9 Zm – <200,000 light years – Revised estimated diameter of the disc of the Milky Way Galaxy. The size was previously thought to be half of this.
• 2.0 Zm – 210,000 light years – Distance to the Small Magellanic Cloud
• 2.8 Zm – 300,000 light years – Distance to the Intergalactic Wanderer, one of the most distant globular clusters of Milky Way
• 8.5 Zm – 900,000 light years – Distance to the Leo I Dwarf Galaxy, farthest known Milky Way satellite galaxy

  10 zettametres

• 24 Zm – 2.5 million light years – Distance to the Andromeda Galaxy
• 30.8568 Zm – 3.2616 million light years – 1 megaparsec
• 40 Zm – 4.2 million light years – Distance to the IC 10, a distant member of the Local Group of galaxies
• 49.2 Zm – 5.2 million light years – Width of the Local Group of galaxies
• 57 Zm – 6 million light years – Diameter of the supergiant elliptical galaxy IC 1101
• 95 Zm – 10 million light years – Distance to the Sculptor Galaxy in the Sculptor Group of galaxies
• 95 Zm – 10 million light years – Distance to the Maffei 1, the nearest giant elliptical galaxy in the Maffei 1 Group

  100 zettametres

• 140 Zm – 15 million light years – Distance to Centaurus A galaxy
• 250 Zm – 27 million light years – Distance to the Pinwheel Galaxy
• 280 Zm – 30 million light years – Distance to the Sombrero Galaxy
• 570 Zm – 60 million light years – Approximate distance to the Virgo cluster, nearest galaxy cluster
• 620 Zm – 65 million light years – Approximate distance to the Fornax cluster
• 800 Zm – 85 million light years – Approximate distance to the Eridanus cluster

  1 yottametre

• 1.2 Ym – 127 million light years – Distance to the closest observed gamma ray burst GRB 980425
• 1.3 Ym – 137 million light years – Distance to the Centaurus Cluster of galaxies, the nearest large supercluster
• 1.9 Ym – 201 million light years – Diameter of the Local Supercluster
• 2.3 Ym – 225 to 250 million light years – Distance light travels in vacuum in one galactic year
• 2.8 Ym – 296 million light years – Distance to the Coma Cluster
• 3.2 Ym – 338 million light years – Distance to the Stephan's Quintet
• 4.7 Ym – 496 million light years – Length of the CfA2 Great Wall, one of the largest observed superstructures in the Universe
• 6.1 Ym – 645 million light years – Distance to the Shapley Supercluster
• 9.5 Ym – 996 million light years – Diameter of the Eridanus Supervoid

  10 yottametres

• 13 Ym – 1.38 billion light-years – Length of the Sloan Great Wall
• 18 Ym – redshift 0.16 – 1.9 billion light-years – Distance to the quasar 3C 273
• 33 Ym – 3.5 billion light-years – Maximum distance of the 2dF Galaxy Redshift Survey
• 37.8 Ym – 4 billion light-years – Length of the Huge-LQG
• 75 Ym – redshift 0.95 – 8 billion light-years – Approximate distance to the supernova SN 2002dd in the Hubble Deep Field North
• 85 Ym – redshift 1.6 – 9 billion light-years – Approximate distance to the gamma ray burst GRB 990123
• 94.6 Ym – 10 billion light-years – Approximate distance to quasar OQ172
• 94.6 Ym – 10 billion light-years – Length of the Hercules–Corona Borealis Great Wall, one of the largest and most massive known cosmic structure

  100 yottametres

• 124 Ym – redshift 7.54 – 13.1 billion light years – Light travel distance to the quasar ULAS J1342+0928, the most distant known quasar as of 2017
• 130 Ym – redshift 1000 – 13.8 billion light years – Distance to the source of the cosmic microwave background radiation; radius of the observable universe measured as a LTD
• 260 Ym – 27.4 billion light years – Diameter of the observable universe
• 440 Ym – 46 billion light years – Radius of the universe measured as a comoving distance
• 590 Ym – 62 billion light years – Cosmological event horizon: the largest comoving distance from which light will ever reach us at any time in the future
• 886.48 Ym – 93.7 billion light years – The diameter of the observable universe ; however, there might be unobserved distances that are even greater.
• >1,000 Ym – >105.7 billion light years – Size of universe beyond the cosmic light horizon, depending on its curvature; if the curvature is zero, the value can be infinite as previously mentioned