AFAIK, a cat should seem a little skinny by human logic. A vet can tell you more about how to tell, like how you're supposed to be able to clearly feel the ribs.

If your boy is visibly round, that's not muscle. A healthy cat is a straight line, or even slightly hourglass shaped.

To be sure, ask a vet. Cats are individuals, so it can vary.

Weigh him and consult with a veterinarian. Don't rely on random Internet strangers to determine healthy weight range for your cats.

Is there a loaf photo?

looks fluffy to me. what's the vet say? go with that.

pets dont feel body shame, its entirely human made concept.

Fat babies need the most attention.

He's just a big strong handsome chonky guy.

Not possible. Cats are incapable of feeling shame!

Responsible and tasteful comments :)

What a handsome guy. This is what I'd call an esteemed gentleman.

This is me kindly requesting more pictures!

Body shaming a cat... Now I have heard it all. Lol.