Medium fits me great - I'm Average build - 5-9 -150 lbs. Length great for being tucked in or worn out. Soft, cool, breathes well, last forever.Wearing these now for 3 years. For me they are perfect and worn every day. I buy most in the dark colors or black. At least 15/20 now hanging in my closet. Only dark color T-shirt cool enough I can wear in the hot summer sun. I Wash (Cold) and Dry (Delicate) - Pull out and hang. Always wrinkle free. I'm still wearing ones I bought 3 years ago that have been through wash at least 100 times and they still look good. Only reason I keep buying more is they are so comfortable I also wear while working and get stuff on them that won't wash out, but now I have several great, comfortable ";spotted work Shirts.";They have become the expected and desired ";go to"; Christmas presents for every guy in the family.