Dr Seuss Cat in the Hat pajamas kids size 10,fit smaller, unisex

I purchased them at Target and my son wore them twice for Dr Seuss day at school. They say size 10 but the shirt looks to run smaller , shirt runs possibly like a street size 8 or 7/8? I can’t remember what size street clothes my son was when he wore it. The pants look to fit a street size 8/10. I can measure if needed. From a pet free/smoke free home.