It is pretty much a one size fits all unless you are very small or very big, but I am "average" (5'6", and "average" weight") and it fits me fine. The hat piece is flimsy but I plan to fix it up the way another reviewer suggested (THANKS!!!) and it isn't as well sewn, the point that comes down in the middle is not well matched/uneven, so I will have to fix that and trim the hanging thread.  Also there is no way to keep the neck piece up or attach it to the hat piece...  With a little work this should make an excellent costume I can use year after year or share with friends and family.  This year my daughter is planning to be sleeping beauty so we should be a cute little team!