The rectangular field of play of American football games measures long between the goal lines, and wide. In addition, there are end zones extending another past the goal lines to the "end lines", for a total length of. When the "football field" is used as unit of measurement, it is usually understood to mean, although technically the full length of the official field, including the end zones, is. White markings on the field identify the distance from the end zone. Inbound lines, or hash marks, are short parallel lines that mark off increments. In most forms of professional football in the U.S., including the National Football League and most forms of indoor football, the hash marks are in line with the goal posts, both being 18 feet 6 inches apart in the NFL and between 9 and 10 feet in indoor football. High school football and college football fields have hash marks significantly wider than the goal posts. The college football standard, which was the previous standard in the NFL, is 40 feet apart, introduced in 1993. Previously, the college width was the same as the high school standard, at one-third of the width of the field. Yard lines, which can run the width of the field, are marked every. A one yard long line is placed near each end of the field; this line is marked at the center of the two-yard line in professional play and at the three-yard line in college play; this is to denote the line of scrimmage for a point after touchdown kick. Numerals that display the distance from the closest goal line in multiples of ten are placed on both sides of the field every ten yards, with arrows right by the numerals to indicate the closer goal line; some fields may denote the goal line with a "G". Weighted pylons are placed on the inside corner of the intersections of the sidelines, goal lines, and end lines. Including the end zones, the total area of an American football field is. The goalposts are located at the center of the plane of each of the two end lines. The crossbar of these posts is above the ground, with vertical uprights at the end of the crossbar apart for professional and collegiate play and apart for high school play. The uprights extend vertically 35 feet on professional fields, a minimum of 10 yards on college fields, and a minimum of ten feet on high school fields. Goal posts are padded at the base, and orange ribbons are normally placed at the tip of each upright for the purpose of gauging wind direction and force. According to the high school rulebook recommendations, the field should be angled at approximately 1.2° upward from each sideline to the center of the field so that the center is higher than the sidelines.
Yard lines
Yard lines are a place on an American football field and Canadian football field marking the distance from the line of scrimmage to the closest goal line. White markings on the field identify the distance from the end zone. Inbound lines, or hash marks, are short parallel lines that mark off increments. Usually, every they run the width of the field. A one yard wide is placed at each end of the field; this line is marked at the center of the two-yard line in professional play and at the three-yard line in college play. Numerals that display the distance from the closest goal line in multiples of ten are placed on both sides of the field every ten yards. Lines marked along the ends and sides of the field are known respectively as the end lines and sidelines, and goal lines.
