My son wanted to be a ninjago for halloween, we could not find a costume for him but we came up with this. It looks a lot like "Kai" from Ninjago and my son LOVES it. We bought the large but probably would have been okay with a medium. He is 7 years old is just over 4 ft tall and is about 70 lbs, we didn't want it to be too small. For the price, the quality is great and he cannot wait to wear it to his school halloween carnival.