I am 5-8 years old 185, I am athletic. I ordered medium (I usually wear medium shirts). The fit was great. The sleeves are short enough to expose the triceps. The shirt is not too tight in the chest and the length of the shirt is good. The landing is very flattering. The material is soft and elastic. To me they are much better (in size and material) than under armor (non BS) and at about a third of the price. I will order 3 more as soon as possible