Tarmac/Open Space How Many A/C fits

[morphin]

How many small/medium/large AC fits into a very large Tarmace Space? (or a large or open Parking spot etc)
Searching the forum i only get a hint that there is a formula, but does the formula only counts the type of AC(small, medium, large, VeryLarge) or the effective Length? (Mostly the length determine the category, but i found that sometimes also the wingspan (for example the RQ-180 UAV with a length of 10m is categorized as Very large AC, but the RQ-4B only as Medium AC, strange!)

I have found with trying that a very large TARMAC space (4 AC) can fit 5 large AC.
Maybe someone has some more numbers? Or knows the fomula?

Thank's