I actually called Safariland the other day to get the scoop. They said your inner belt is the actual measurement of your waist through your belt loops, so for me, 40, then for the outer belt add 2. Their numbers do not necessarily correlate to pant size. I wear a 36ish pant size, 36 is a bit loose, but 34 is a bit tight. So per their directions I need a 40 inner and 42 outer. I don't have my belt in hand yet so I can't help with the overall dimension question.