These were perfect for our upcoming Disney trip. Used them for diy heat vinyl transfer t's. Our kids ages are 15, 9, 8, and 5. For the 15 year old we ordered an adult sz xsmall, the 8 and 9 year old we ordered a youth small, and for our 5 year old son we ordered a xsmall youth. After reading the previous reviews I chose to order a size smaller since they do run about one size larger. I usually wear a size medium in an adult unisex, the adult small was perfect, I'm 5'1 about 123lbs. My husband wears between a medium and large in men's depending on the brand. He's 6'1 180 lbs, the Medium fit him just right, but we also ordered an adult size Large and he felt that it was a more comfortable fit as it might shrink a bit with washes. Over all we will be ordering again! Shipping both times was extremely prompt! Hands down this company has our service for t shirts from here on out! We are promoters for a direct sales company and order lots of shirts for advertising. We are excited to find a solid company that keeps its simple and prompt! Thank you!