I got this for my 9 year old son for Halloween. He is average build and height and a medium worked well for him. We did not find the sizes to be off like other reviewers. The costume was of decent quality. There are a lot of cheap ones out there and this was not one of those. My only complaint was that the belt was a little hard to get on since it's kind of tight and you have to pull it over their head or up from their feet. All and all though I thought it was a good value for the price and he was definitely happy. His 6 year old brother was Anakin and they thought they were pretty awesome together.