The distance between the two 30 yard lines on a football field is 40 yards.
• The football field
Football is played on a field that measures 120 yards by 53.3 yards. The short boundary lines are called end lines, while the longer boundary lines are called sidelines; both of these are out of bounds to the players.
Ten yards from both end lines are the goal lines, which are a 100 yards apart. The space between the end line and the goal line (which includes the goal line, but not the end line) is called the end zone.
• Yard lines
These cross the football field every five yards, from sideline to sideline, but are only numbered every ten yards from the goal line to midfield, which is the 50 yard line. If you imagine the football field laid out, with the 50 yard mark in the middle and then being marked in increments of ten yards back towards each goal line, you will be able to see that there are 40 yards between the two 30 yard marks.
• Hash marks
Hash marks, also known as inbounds lines, run at one yard intervals at right angles to the sidelines, near to the middle of the field. Play always starts with the ball on or between these hash marks. Sometimes a football field is referred to as a gridiron because the pattern of the lines gives it the look of a cooking grill.
• The football field
Football is played on a field that measures 120 yards by 53.3 yards. The short boundary lines are called end lines, while the longer boundary lines are called sidelines; both of these are out of bounds to the players.
Ten yards from both end lines are the goal lines, which are a 100 yards apart. The space between the end line and the goal line (which includes the goal line, but not the end line) is called the end zone.
• Yard lines
These cross the football field every five yards, from sideline to sideline, but are only numbered every ten yards from the goal line to midfield, which is the 50 yard line. If you imagine the football field laid out, with the 50 yard mark in the middle and then being marked in increments of ten yards back towards each goal line, you will be able to see that there are 40 yards between the two 30 yard marks.
• Hash marks
Hash marks, also known as inbounds lines, run at one yard intervals at right angles to the sidelines, near to the middle of the field. Play always starts with the ball on or between these hash marks. Sometimes a football field is referred to as a gridiron because the pattern of the lines gives it the look of a cooking grill.