I'm 5'4", 145 lbs, 35-31-37, petite proportions. I ordered a small and it's great! I fold the cuffs up a little bit to help the length of the sleeves (I expect this with all normal-proportion tops). I can button all of the buttons but it would be uncomfortable to button more than just the top two, as my hips and booty make the bottom part tight. Still, with just the top two buttoned, it looks super classy and professional and still protects my jeans from chemicals. Washes well without shrinking, too!