Field goal range is the part of the field in American football where there is a good chance that a field goal attempt will be successful.
A field goal is normally 17 or 18 yards (7 or 8 yards in Canadian football) longer than the distance of the line of scrimmage to the goal line, as it includes the end zone (10 yards) and 7 or 8 yards to where the holder places the ball. In Canadian football, the goal posts are on the goal lines, in front of the end zones. Therefore, if the line of scrimmage is at the 30, the field goal would be 47 or 48 yards (in American football) or 37 or 38 yards (in Canadian football).
From 1932 to 1974 the field goal in the NFL was located at the goal line, similar to Canadian football, so only 7 or 8 yards was added to the distance from the line of scrimmage.