These fit true to size. I ordered the XL. The only knock on them is that they don't have the finger loops to help take them off after a ride. There is a tab at the bottom of the glove to help pull them on, but its not that effective at taking them off. If I could give 4 1/2 stars I would, not having the loops is a minor annoyance. They breathe well, and the material in the palms keeps your hands on the bars even when your sweating. I have worn a different brand that has some plastic grip pads on the palm, and those get slippery on a road bike when your hands sweat. Ive only worn these twice, so I cant speak to durability, but Giro products are generally well made.