How big will your puppy get? Meet The Puppy Predictor
If you’ve ever brought home a puppy, you’ve asked the question out loud at least once — usually while they’re asleep in your lap with paws that look two sizes too big: how big are you going to get? The breeder gave you a range. A neighbor swears you just double their weight at four months. Somebody else says watch the paws. Nobody really agrees, and the puppy isn’t telling.
So I built a little tool that does the actual math. It’s called The Puppy Predictor, and it’s here:
Why not just double the four-month weight?
Because puppies don’t all grow on the same clock. A small dog is basically done growing by its first birthday, while a giant breed is still filling out its frame at two years old. The fraction of their final weight a pup has reached at any given age depends a lot on how big they’ll end up — so a single shortcut that works for a Dachshund falls apart on a Great Dane.
The Puppy Predictor uses the real, size-adjusted growth curve instead. Tell it your puppy’s breed — or just pick a size if they’re a happy mystery mix — how old they are right now, and what they weigh today. It places your pup on the curve for their size and gives you a grown-up weight range, a little chart showing where they are now and where they’re headed, and roughly when they’ll stop growing. It even prints a keepsake, the same way the Dog-Years Translator does.
It’s an estimate — and it’s honest about that
I gave you a range on purpose, not a single fake-precise number, because every puppy is its own surprise. Diet, sex, when they’re neutered, and plain individual genetics all nudge the final figure. Your vet, who can actually see and feel how your dog is built, is always the better guide. But for satisfying that 2 a.m. “how big are you going to be” curiosity, it’s a pretty fun place to start — and a good nudge to feed a big-breed pup for a slow, steady, joint-friendly climb rather than a growth spurt.
And nothing leaves your browser
Like the rest of the little tools in the workshop, every bit of this runs right there on your phone or laptop. No account, no ads, and nothing about your dog is ever uploaded — it’s just arithmetic, running quietly on your own device.
Find out how big they’ll get →
— Jamie
