It will also depend on bloodline and breed of the dog. Many breeds of a larger size develope at a slower rate. Slower growth means a sound foundation. Have a large dog that has a fast growth and you will have joint and hip problems.
My apbts have all finished growth by 3. Usually in that 2-3 year range.
At 10 months, both my pups weigh 51lbs. They don't look like they would though. Dillon is much more muscular that her littermate Sherry. The breeder I got them from told be their bloodline is RazorEdge. I've researched the bloodline and know that they don't grow tall but grow out. Once I figure how to post with pictures, I'll add some of my pups.