I ordered this for my 8 year old and he wears a size 10 of each brand perfectly but I had to order a size 14 to fit him as he is very small but the pants are a bit longer and a bit loose He will be one Wear belt but fits everywhere.
Size 10 wouldn't even close and size 12 was a little tight and he didn't have room for a cruise due in a week and another cruise in 3 months so he could wear them both times!