I just googled it after your comment and the conversion of football field came in terms of acre or hectare so I think Area is suitable. I will see what most people are using and based on that I will set its value.

I've never heard of anyone comparing to a football field in the Area domain. Of course this is cultural, but at least in the US - the length is what is commonly compared.

No problem. I will add in both to make Area and Length users happy!

Definitely country-specific, I'd expect it to be used to describe areas (and football stadiums be used to describe "number of people"). But footy fields in Australia are typically oval shaped! "Olympic swimming pools" can be used for length, area or volume (but "Sydney Harbours" are only used for volume).

PS just tried the tool and couldn't find any of the above "units", not even "football fields".

just added football field to the length. I will look for the units that you have mentioned. If they are widely used, will definitely add them.

I agree that it's most commonly an expression of area. I think the length alternative is valid but pretty rare by comparison.

I've never heard it used for area. "Length of x football fields" is the only comparison I've ever heard in the US.

Thanks for feedback. Added football field to the length category.

I chose 120 yards and added that to length category.