Buy one size smaller if you want a "regular" fit and 2 sizes smaller if you want a "slim" fit. I'm 6'2, 195lbs and my size is usually large for t-shirts with the exception of brands like Abercrombie, Hollister, Diesel, Armani Jeans etc.. My size for those is XL because they're muscle fit and I'm not that muscular..lol. Either way, I'm returning and I'm going to buy a Medium because the large size I bought is VERY large, even if my belly decides to grow even more the t-shirt will still be large. It would be appropriate for someone 6'7 tall with 350lbs. Other than that the quality is excellent and Amazon's service supreme as always!