When ordering rash guards it is important to understand their designed for proper fit. Rash Guards are designed to be worn skintight and are therefore manufactured accordingly. If you wear a large polo shirt, and order a large rash guard, you will have 2 different fits. Your large polo shirt will fit loose and hang over your body while the large rash guard will be skintight and shorter. If you are looking for the looser fit, you'll need to order up to 3 sizes larger in the rash guard.