I love these t-shirts!
As every other review already states, they are longer than your normal t-shirt. That being said I am 6'2" and they don't go anywhere near my knees... just down to the bottom of my pelvis bone/groin. They are just the right length for tucking in.
These shirts are also very comfortable. The material is nice, thick, and soft. I'm replacing all of my under-shirts with these. No more pulling out when you bend over! hah