Just got my xs crew neck. I'm 5'7", 132 lbs. Definitely getting a small next time. My nipples pierce through the xs. Fabric is great though, and the sleeves are perfect. Most t shirt sleeves either flare out on me or hug my bicep like a muscle shirt. The sleeves on Everlane tees are just right. This shirt will make a great undershirt for crew neck sweaters and I'd size up for tees to wear on their own.