My 11 year old soccer and karate boy loved the X-Temp Hanes boxers but personally found them to be too tight. I ordered size L (14/16) because he wears size 12/14 shirts and size 14 pants (barely a 14) and they were tight. We ended up buying them in size XL (18/20) and they fit perfectly. If your son likes very tight underwear that might be fine, but we weren't looking for compression underwear so we recommend going up a size. If it helps at all, he weighs 95 pounds and is about 5 feet tall.
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