Information on supply usage by ground units is sparse in the manual, therefore I have run my own
tests to get figures. In some instances these are probably exact formulas, though mistakes may have
been made. In other instances, supply usage is influenced by different factors, some unknown. In
these cases, number given here are little better then (educated) guesses, so I advise players to build
in decent margins so your units will not run low on supplies.
The supply usage for units out of combat is easily calculated. In the unit screen, "supply required' is given. This number is the approximate use of supplies by the unit in a single month when it does not move or engage in
combat. The formula for supply use during one day is the following.
''Supply used in a single day = Supply required/30 , rounded up. (This rounding up will lead to a
higher actual supply usage for units then the 'supply required' number)
The supply usage relative to supply usage is not influenced by OpMode, fatigue, disruption, admin skill of leader, ... The only factor that could "break" the formula, was a supply shortage, which reduces the supply used. I also could not find any factor that changed the 'supply required' of rear area unit (terrain, base
size, ...), apart from over-stacking them on islands. The formula for finding supply required is
approximately ''Ready devices + 0,5*Disabled devices''
In combat, supply use seems to be correlated to losses taken. The better combat goes for one side, the less supply they will use. This makes calculating supply needs for combat units tricky, as many factors influence combat and thus the supply usage. The range of supply use during combat is very large, one series of tests saw increases ranging from +5% to +300%.
Combat also has a long term effect on supply usage. Combat increases the "supply required" for participating units, leading to higher supply usage in the following days, over time this will return to its original level.