Please use the official manufacturer's size guides to help you select the correct size. Width measurements are across the chest, from armpit to armpit. All sizes are approximate, and the manufacturer allows a 2.5cm tolerance on all measurements. If you're in doubt about the size you need, it's best to err on the side of caution and order the next size up. These tees are printed to order, so they're unique to the buyer. We only offer exchanges and/or refunds if the item we have supplied is defective, not because it doesn't fit.