I think my kitten stopped growing...?

Meet Sebastian. He is a silver tabby, a DSH. I've had him since he was 10 weeks old and he will be a year this coming Monday. What I've noticed about him is that, when he reached 6 months, he stopped growing. He has been gaining weight, but he is no talker.
Is it true that they keep growing till that are 2 years old? Is this a normal thing that he stopped growing? I'm just curious. I've seen cats bigger than him that are around the same age.

@SebNari96

Some breeds turn adult at 1 year old and some at 3 years. DSH like yours most likely turn adult at around a year or so and will stop growing.
Is he neutered? If he is not, proably he'll be a little smaller than if he's neutered. And make cats are bigger in size than female cats.
Is he on dry food? Dry food are full of carbohydrates and that will make them fat but if a cat eats a lot, over fed with wet food will also make them fat.

Can someone please help me and answer ny thread I'm really worried

@kallyn ritchie

MOD Norachan had answered your thread

He is neutered. Has been since he was 8 weeks old.

As for food, he isn't on the best of food. It's Purina Kitten Chow. I am planning on changing his food soon to something even better. Either Orijen or Taste of the Wild.