Built on 1.07 million real dogs
How big will your puppy get? Let the data answer.
Type in an age and a weight and get a likely adult weight with an honest range. Save weigh-ins and watch the range tighten, with a chart your vet will actually want to see.
- No sign-up for the calculators
- Curves from a published study
- An honest range, not fake precision
Example Labrador puppy, 14 weeks
54 to 80 lb
likely adult weight, 80% range
Six free calculators
Each one runs in your browser, shows its working, and tells you how sure it is.
Puppy weight calculator
Age and weight in, adult weight range out
OpenPuppy growth calculator
Plot several weigh-ins and see the curve
OpenDog weight calculator
Adult weight forecast, healthy range and calories
OpenDog size calculator
Toy, small, medium, large or giant
OpenDog pregnancy calculator
Due-date window and week-by-week guide
OpenCat age calculator
Cat years to human years and life stage
Open
Looking for a table? See the puppy weight chart by age.
Why the old rule fails, and what we do instead
“Double the weight at 14 weeks” is right for some dogs and badly wrong for others. Puppies of different sizes grow on different curves, so we measured how much of its adult weight a typical puppy has reached at every age, for six size classes, and use that.
Then we tested it on dogs it hadn't seen, and report the errors as they are.
Read the methodsTypical error on unseen puppies
| Age at weigh-in | Median error | 80% range held |
|---|---|---|
| 8 to 11 weeks | 17.8% | 83.6% |
| 12 to 15 weeks | 14.8% | 83.5% |
| 16 to 25 weeks | 11.5% | 84% |
| 26 to 38 weeks | 8.7% | 85.4% |
| 39 to 52 weeks | 5.9% | 87.4% |
Error is the gap between forecast and final adult weight, as a share of adult weight. One weigh-in only; more weigh-ins do better.
The calculators are the start. The tracker is where it pays off.
A forecast that gets sharper
Every weigh-in narrows the adult-weight range. You see it happen on the chart, not just a number that jumps around.
Off-curve alerts
A puppy growing much faster or slower than healthy dogs, or losing weight, is flagged while there's still time to act.
Feeding that follows growth
Daily calories and grams from the NRC growth equation, using current weight and predicted adult size.
Litter mode
Daily weigh-ins for every pup, collar colours, a first-two-weeks weight-loss warning and whelping checklists.
Vet and buyer PDFs
A clean growth and vaccine summary for the vet, and a go-home packet for buyers.
A puppy coach that knows your puppy
Ask questions with the weights, breed and age already in context. Emergency signs are redirected to a vet.
Free for one puppy. Pro from $5.99/month. Litter Pass $19 once.
No trial tricks. The free plan stays free.
From the guides
All guidesPuppy weight chart by age: what's normal, and what the charts get wrong
How much a puppy should weigh at each age, shown as a share of adult weight for every size class, with the data behind it and how to read your own puppy's numbers.
How big will my puppy get? Four ways to guess, ranked by how often they're right
Four methods for predicting a puppy's adult size, from paw size to weigh-ins, and how accurate each really is. Includes the data on how far off a single weigh-in can be.
Dog pregnancy week by week: what happens and what to do
A week-by-week guide to dog pregnancy: what happens, what to feed, when to see the vet, and when the puppies are due, with veterinary sources.
Common questions
How accurate is the puppy weight calculator?
On puppies it had never seen, a single weigh-in at 8 to 11 weeks was off by a median of about 18% of adult weight, falling to about 12% at 16 to 25 weeks and 6% at 39 to 52 weeks. The 80% range held the adult weight 84% to 87% of the time. That's why the tool gives a range and a chart, not a single number.
Where does the data come from?
The anonymised weight records that Waltham and Banfield Pet Hospitals published with their 2017 PLOS ONE growth-chart paper (CC BY 4.0). We re-analysed them: about 1.07 million dogs and 5.4 million weigh-ins, grouped into six size classes. The methods page has the detail.
Is PupCurve free?
All six calculators are free with no sign-up. A free account tracks one puppy with five weigh-ins. Pro is $5.99 a month or $39 a year, and the Litter Pass is a $19 one-time purchase for breeders.
Does it replace my vet?
No. It gives you a picture of how your puppy is growing compared with healthy dogs. If your puppy loses weight, stops gaining or seems unwell, call your vet.
Does it work for mixed breeds?
Yes. Weigh-ins alone are enough: the model works out which size class your puppy is following. Add the parents' weights or a breed if you know them and the range tightens sooner.