I have two 3 year old boys. They are different in size and build. I ordered the XS expecting them to be large and they are. The Twin A is a real 4T and a bit too big for it. He has room to grow, but he hits him almost perfectly on the shoulder. This is too big a shirt for Twin B at the moment. They have been worn and washed several times. They have retained their softness and the color does not fade like some. I think it would be perfect for the average 5 year old.