When do puppies stop growing?

The domestic dog (Canis familiaris) is totally unique in that it comes in more sizes and shapes than any other one species on the planet. With such huge variations in dog breeds and types, it’s not surprising that there are also significant differences with their growth – so the answer to ‘When will my puppy stop growing?’ is… it depends!

If you have a toy breed, such as Chihuahua or Shih Tzu, you’ll probably find that they have done nearly all their growing by six months. Medium to larger dogs take a bit longer, and dogs such as Labradors will take around a year to stop growing and longer to fill out and mature.

And if your puppy is one of the giant breeds, like a Bernese Mountain dog, then they will continue to grow for anything up to two years! After they have reached this stage, your dog won’t grow any taller, but exactly like human teenagers, may still continue to fill out a little as their muscle and fat changes into that of an adult.

Don’t panic if your puppy’s growth seems to suddenly increase – or stop!  Just like children, they will all have growth spurts interspersed with periods of time where their growth slows a little – and the extremely rapid growth rate of puppies will slow as they get closer to their final size.

How big will my puppy get?

There are many factors that influence your puppy's adult size, with breed being the most obvious one. If you have a purebred dog, you will be able to easily find out the likely size of your puppy by reading about the breed, and of course, your breeder will be able to give you lots of information.

The simplest way to tell is find out how big their parents are, as that will give you the best idea. If you have got your puppy from a reputable breeder, you will have already seen the mother and know what size she is, and the breeder will be able to tell you the size of the father.

Adult males are generally larger than females, but even within specific breeds there can be quite a bit of variation – and even when you know the parents, there can be throwbacks to larger or smaller individuals.

If your puppy is a crossbreed, it’s certainly a little harder to know how big they will grow – even if you know who both the parents are. There’s no guarantee that your puppy will end up as an average of the two parents, and your puppy’s adult size may be quite different to what you expected – and sometimes a crossbreed will end up bigger than both parents If you don’t know the parents. It will be bit of guesswork based on the breeds that you think make up your puppy’s parentage.

It’s a relatively short time that your puppy will be small, so enjoy the journey (and sometimes the mystery!) of watching your new family member grow into a healthy adult dog.

Last reviewed by expert behaviourist Carolyn Menteith on 7 July 2024.