Dog Size: How to Predict Your Puppy’s Adult Size

Dog size is not an exact science. In fact, even a single purebred litter can produce an alpha and a runt who vary in size. If you’re wondering how big your puppy will grow and how fast, you’re not alone.

Of course, they’re so adorable. But also, so much heavier than last time they sat on your lap… this morning.

Here are some clues to work out your puppy’s eventual dog size.

How big will my puppy get for their full dog size?

If you have a pedigreed pooch, chances are you can guestimate more accurately how big (or little) your pooch will be. A female will most likely grow to a similar size as her mother, and a male a little bigger. However, if your pup was the runt of the litter, they might stay smaller than you expect.

If you haven’t actually met the parents, then Purina’s dog chart can tell you the size and weight of different breeds.

If you’ve adopted from a shelter (yay – read our article on bringing home an adopted dog!) and don’t know the breed, chat to your vet. A pup’s fur holds clues as to its lineage. Sometimes vets can use this to make an educated guess.

You can even do dog DNA tests to discover your pup’s ancestry.

But what about its dog-sized personality? You might be interested in finding out what the kindest dog breeds are.

Tell-tail signs

As we know, every pack has its alpha and its runt of the litter. The more clues you can garner from your very own puppy, the better. Where did it sit in the pack?

Other tell-tail (make that wagging tell-tail) signs include your puppy’s paws or any loose and saggy skin. Technically, your pooch will grow into their paws and fill out their loose skin. So, if your pup has big paws or a big loose blanket of skin, s/he possibly won’t always fit on your lap…

Happily, if puppy does outgrow your lap, it turns out sleeping with your dog in your bed has some great health benefits.

When is a puppy fully grown?

Pint-size pooches like Chihuahuas are fully grown by six months. Dogs on the other end of the scale, like Great Danes, can continue to grow for up to two years.

This is because big breed dogs take longer to reach their full size while small breeds do so faster. In other words, the bigger a dog will become, the more time they need to get to destination fully-grown. Read about the biggest dog in the world!

Not all growth cycles are created equal.

Pssst… this next difference holds a clue for working out what your puppy’s full dog size will be. Read on for more…

Calculating dog size with growth cycles.

According to Vet Babble, an educational website run by vets, puppies double in size in their first week after birth. After this, puppies grow 5-10% a week. Then at the six-week mark, small and big dogs part ways in their growth cycle.

From the six-week mark, small dogs grow about 140 grams a week, whereas big dogs grow about 1kg. Vet Babble also has a growth calculator which will give you a healthy estimate.

Dog happiness is bigger than dog size

Of course, whether your dog is big or small, you want to ensure it’s healthy and happy. A key way of doing this is to have pet insurance. Non-routine vet visits, tests, surgery and other medical treatments can cost a pretty penny – and often the need for them is unforeseen. 

Dog insurance covers these costs so you can think about pooch rather than your pocket.