The Ancient Egyptian palm has been reconstructed as about. The unit is attested as early as the reign of Djer, third pharaoh of the First Dynasty, and appears on many surviving cubit-rods. The palm was subdivided into four digits of about. Three palms made up the span or lesser span of about. Four palms made up the foot of about. Five made up the remen of about. Six made up the "Greek cubit" of about. Seven made up the "royal cubit" of about. Eight made up the pole of about.
Ancient Israel
The palm was not a major unit in ancient Mesopotamia but appeared in ancient Israel as the tefah, tepah, or topah. Scholars were long uncertain as to whether this was reckoned using the Egyptian or Babylonian cubit, but now believe it to have approximated the Egyptian "Greek cubit", giving a value for the palm of about. As in Egypt, the palm was divided into four digits of about and three palms made up a span of about. Six made up the Hebrew cubit of about, although the cubits mentioned in Ezekiel follow the royal cubit in consisting of seven palms comprising about.
Ancient Greece
The Ancient Greek palm made up ¼ of the Greek foot, which varied by region between. This gives values for the palm between, with the Attic palm around. These various palms were divided into four digits or two "middle phalanges". Two palms made a half-foot ; three, a span ; four, a foot ; five, a short cubit ; and six, a cubit. The Greeks also had a less common "greater palm" of five digits.
Ancient Rome
The Roman palm or lesser palm made up ¼ of the Roman foot, which varied in practice between but is thought to have been officially. This would have given the palm a notional value of within a range of a few millimeters. The palm was divided into four digits of about or three inches of about. Three made a span of about ; four, a Roman foot; five, a hand-and-a-foot of about ; six, a cubit of about.
Continental Europe
The palms of medieval and early modern Europe—the Italian, Spanish, and Portuguesepalmo and Frenchpalme—were based upon the Roman "greater palm", reckoned as a hand's span or length. In Italy, the palm varied regionally. The Genovese palm was about ; in the Papal States, the Roman palm about according to Hutton but divided into the Roman "architect's palm" of about and "merchant's palm" of about according to Greaves; and the Neapolitan palm reported as by Riccioli but by Hutton's other sources. On Sicily and Malta, it was. In France, the palm was about in Pernes-les-Fontaines, Vaucluse, and about in Languedoc. Palaiseau gave metric equivalents for the palme or palmo in 1816, and Rose provided English equivalents in 1900:
England
The English palm, handbreadth, or handsbreadth is three inches or, equivalently, four digits. The measurement was, however, not always well distinguished from the hand or handful, which became equal to four inches by a 1541 statute of Henry VIII. The palm was excluded from the British Weights and Measures Act of 1824 that established the imperial system and is not a standard US customary unit.
