Licensed Mart Men's GB Rashguard UPF 50+ Swim Tee Size Scale Laying Flat, " Arm pit to Arm pit" / "Top Collar to Bottom Hem" , this is an Accurate Scale With 0.5" variant Due to Manufacturing Process. Small 18/24 Medium 19.5/25 Large 20.5/25 X-Large 21.5/26 XX-Large 23/26.5 Machine Wash Cold, Tumble Dry Low, No Bleach This is a Rash guard, Rash guards are meant to be tight on the body like a Glove. True Rash Guard Material 92% Polyester 8% Spandex, UPF 50+ rating