Snowboard pants usually run very big on me so I ordered an xs. The length and waist was great but the thighs were way too tight. I could hardly move in them let alone wear layers underneath. I exchanged for a size up and the thighs are much more comfortable but the pants are a little too long. Overall though, they work great for snowboarding.
I ordered a medium but should have gotten a small. The slim fit is awesome! They aren't too slim though that you couldn't add layers underneath. I will definitely be looking for another pair in my size of a similiar burton snowboard pant.