How big should my staffy get?

I have a purebred male staffy and he has just turned 1 year old.
My boy Rambo is so small still although he is very stocky (We seen and met his parents so we know he is a purebred).
He was the size of a baby chihuahua when we bought him at 8 weeks old.
I was wondering when do they stop growing?

Thanks!

Hi this is only my take on this subject after 1 year he would of got his height and the next 12 - 24 months he should fill out then after that he or she is about the size they are going to get ( unless you feed him to much and his or her belly will get big lol )

Dogs (according to the breed standard) should be between 36 - 41 cm (14 - 16 inches) at the withers and should weigh between 13 - 17 kg (28 - 38 lbs). There are still many variables though. If both mom and dad are big, the pups might be bigger than breed standard, and vice versa, when both mom and dad are small, the pups might grow up to be smaller.

Staffs don't stand very high. Maska is 1 year old, and he has reached his height roughly round 8 months. He's been the same height since, but now he is setting out. Staffs grow for quite some time, because in year 1 they reach their height, year 2 they start filling out and even into year 3 their heads still broaden.
Maska's weight varies between 18.5 - 19.5 kg, and he is becoming very stocky.

Our Loki is tiny. She was the runt of the litter (but we still chose her), and when we picked her up at 9 weeks, she was only 1.8 kg. She is four months old now and only weighs 6.5 kg. Other people on here have younger female pups that weigh 10 kg.

Also, you must remember, dogs grow at different rates and they are all different.

Hope this answers some of your questions

They tend to grow upwards in the first year, and fill out muscle wise after, Moo is 3 and is still developing. Having seen the parents will give you a good a idea