As others have said, this shirt fits me the same as my other regular XL t-shirts. I'm Maye, 5'11", 210lbs, 44" chest. I bought these shirts to use in place of the more expensive sun shirts. I also wanted to use them when I went swimming on vacation. They worked great. Let me tell you what I experienced. I put the shirt on and it looked like my regular XL t-shirt. The sleeves were a bit longer, but what could you expect? Remember that the manufacturer must offer a shirt that fits multiple body types that require an XL size. Some people have long arms, others not so much. I just rolled up my sleeve. Problem solved. The shirt was loose overall, which I like. I spent a lot of time in the sun on vacation and the sun protection worked great. Keep in mind that this isn't full sunscreen, just SPF 50. Then I went in the water with my shirt on. Of course, the shirt got just as wet as my t-shirt and the fit, as expected, was a bit sloppy. The sleeves seemed to sag a bit, but I overcame that by simply pulling the sleeve up over my shoulder. I had no trouble swimming and snorkeling in this shirt. how can you know Normal expensive sun shirts have a tighter fit. If you would like this I would suggest ordering a smaller size. If you want it primarily for swimming I would scale it down. If you want him to both swim and lounge like me, the size was just perfect.