I don't think he wanted to know the specifics of a two-pence coin, but was rather lamenting the overuse of rough and localized units in lieu of logical and standardized ones.

So about 0.00237 football fields, then.

If it's a tiny tiny football field.

"American" or "Association" football ? (Ironically, FA-aka-soccer fields do not have a standard size, only standard boundaries, so they would not be a valid unit of length anyway...)

I used an American football field, and only the length, and my math could be off. When I read “X football fields long” I assume American football, and when I read “X football pitches long” I assume Association football. Or at least I would have, if I had ever encountered it.

“Football field” as a standard is, I believe, based on American football. Which is odd, because American football is non-migratory.

Non-migratory USA-only standards seem, well... Standard?