the sleeves of these shirts are disproportionately short compared to the body, ridiculously short. I ordered 2 different sizes (L and XL) and returned the large one because looking at the shirts I could tell the sleeves were more like 3/4. Unfortunately I washed the XL hoping they would fit my slim 16 year old girl. Not even close. The body fitted, but the sleeves were 6 inches shorter. upset.

You can't go wrong at the price of 2 packs. The sizes weren't clear so I bought several sizes for my two sons. My 8 year old (58lbs and 4ft 2.5in) runs small. So I would say the small size is a size 8. My 13 year old (101 lbs 5ft 2.5in) fits in the large size. Size XL was too big for him and size M too small. If I had to figure it out, I would say Medium is a youth size 10-12, Large 14-16 and XL 18.