I am US size 36 I bought a size 36 for the first time, boom! too small haha but my wife likes it so she took it. Ordered another size 38 which fits when I wear tight clothes. If you sag a little or wear loose clothes for work I say go 2 sizes up, you are welcome and good luck. Oh, they're a little lighter than I expected from my shoes, but I don't have OCD