I'll echo everyone here. I usually wear a 42" waist (My USAKs are 42s, hand sewn is a 42, and the hand sewn I have on order from Matt is being made at 42"... and the rest" But, I found when I bought my first SWK (Nighstalker standard) that it fit at the tightest notch. So, the next two I ordered (Wallace Economy and a Heavyweight Saffron) were both in a 40 and they're perfect.)