The shirt seemed to run a little small, yet the pants were perfect. But I'd go the next size up. I got a med 3-4 for my at the time 2 year old who is normal height. This costume is SO cute. My 2 year old has worn this I can't even tell you how many times. He wore it at least 3 different times for Halloween parties. And he would just put it on to wear around the house and watch Pirates of the Caribb. and play swords. The costume is put away, but the sword is not (sword does not come with it, but I bought a cheap $2 one from Amazon and although the handle has broken, we just used black electrical tape and it fit the bill)....we've had it 6 months and it's definitely gotten it's use. The costume is just cute as it can be.