LOVE these shorts! great material, good padding. I am 5'10" and I am a size large. I have bigger thighs from years of soccer and I know I wouldn't have been able to fit into a medium. I feel as if they fit true, no need to size up. My leg is 24 inches diameter (At the largest part of my thigh) and from crotch to knee is 15 inches. Hopefully that will help you if you are debating on which size to get.