I bought this shirt to wear with a fancy suit costume. I wear a Large and that's what I bought. Too small, even though it's kind of a stretchy poly material. Forgot this was made in China and their sizing is always one to two sizes too small. So I returned it and bought an XL and it fits great. Keep in mind that this is a "fitted" shirt, so if you have any kind of a gut, it's going to be too tight. But the shirt looks great and I would totally buy it again.