Okay, these are honestly the same material as pajama jeans. (I should know because I own 3 pair of them!)  I'm 5'4" and weigh 147 pounds. I wear a size 10/12 in pants and I ordered a large. These are too long. I have to roll them up. They are a tad bit loose but I'm afraid if I order mediums they might be too tight. Not sure if I want to gamble that.  However, they are super comfy and I can wear them to work and also casually with boots. They don't slip down even when I squat down or bend over.  The back pockets fit my galaxy s8 comfortably if need be. I wish I could find some that were this comfy but looked more like real jeans. I have some jeggings but I haven't found any that were that comfy. If I take a chance and buy mediums I'll be back to edit the review.