These definitely run small. The 18 plus are smaller all over than my 505 misses 16. If I cared whether I wore plus or not that might bother me. The big advantage to these is that they stretch. No pinching around the waist or hips when I sit or crouch down. Seriously comfortable and no rivets on the coin pocket to scratch up my phone. Win. Only reason why I didn't rate these 5 star is because they don't come in different lengths.