How wide is an arena football field? The field is 85 feet wide, the same width as an NHL Rink. How wide is a NFL field sideline to sideline? The dimensions of an NFL field are 360 feet long (each end zone is  30 feet long) and 160 feet wide. There are two hashmarks on the  field, each one being 70 feet and nine i…nches from the closest  sideline. 1 person found this useful.