Is 48X24 the right size???

Ok, I lost sleep on this one. I'm getting ready to build a custom board with my family and thinking about the field size. If your field is 48 inches long, you have to compress 120 yards into that, which gives you .4 inches per yard on your field. (48 inches divided by 120 yards = .4 inches)

Ok, the actual width of a football field is 53.33 yards. If you divide that into 24 inches for the width, you get .45 inches. That may not sound like much of a difference, but it matters. It means you don't have actual square yards on your field and your actual proportions are not exact.

What we actually need to do to have actual square yards on our field is multiply the 53.3 yards by .4, giving us 21.32 inches for our width. Therefore, our actual field width should be 48 inches long by 21.3 inches wide (not 24 inches). Comprende?

So here's the question; why do we use 48 x 24 field covers instead of 48X21 or 22? Is it a matter of convenience or does anyone else use these more true to life measurements?

Thanks, Brian