Usually underwear sizes runs on the small size. If you wear a large, get x-large. if you wear x-large, x-large will fit tight. NOT the case with these mens briefs. They run way over size. If you wear X-large I'd suggest getting medium. Reduce your order by 2 sizes. Anyone want to buy an enormous fat person sized underwear @ X-Large? For someone that needs XXX-Large? Wasted money.