Hammies sizing is based on US pants sizing (size 32 means 32 inch waist), so if you wear a size 32 in jeans, then you're a size 32 in Hammies. If you don't know your waist size, measure the waist of your favorite shorts or pants in inches and multiply that by 2 (16" across x 2 = 32"). If you're in between sizes, we suggest sizing down.