Man I would guess this.....I wear 34x34 in jeans and it's a hair big on me, my plan was to get them where I could wear pants under them and it would work perfect for that, I just decided I wanted a pair to fit like normal overalls, I would say Large means up to 40 waste and maybe up to 36 length with the adjustable straps, I put them on over gym shorts and a t shirt and it was just a hair baggy not bad, I put them on over jeans and a hoody and it worked fine