Mixed breed puppy weight calculator
How big will your mixed breed puppy get? Enter the mother’s and father’s adult weights, plus your puppy’s age and current weight, to estimate adult size. Don’t know the parents? Pick a size group instead.
How the mixed breed estimate works
For a mixed breed, the parents are the best clue to adult size. The calculator averages the parents’ adult weights to choose a size group, because small dogs finish growing much sooner than big ones. It then works out how far through that group’s growth curve your puppy is likely to be at its age, and scales up from today’s weight.
The parents’ weights also act as a sense check. If the estimate lands far outside them, the calculator flags it, so you can double-check the numbers or mention it to your vet.
Worked example
A puppy’s mother weighs 40 lb and its father 60 lb. Their average, 50 lb, puts the puppy in the large size group. At 16 weeks, large-group puppies have typically reached about 45% of adult weight. So a 25 lb puppy at 16 weeks is heading for roughly 25 ÷ 0.45 ≈ 56 lb, shown as a range of about 47–65 lb because puppies vary.
When do mixed breed puppies stop growing?
| Parents’ average adult weight | Size group | Reaches adult weight at about |
|---|---|---|
| under 12 lb | Toy | 12 months |
| 12–25 lb | Small | 12 months |
| 25–50 lb | Medium | 15 months |
| 50–100 lb | Large | 18 months |
| 100 lb+ | Giant | 24 months |
Tips for a better estimate
- Ask the breeder or shelter for both parents’ adult weights, not just the breeds.
- Weigh your puppy on a scale, ideally at the same time of day, every 2–4 weeks.
- Recalculate as your puppy grows: an estimate at 5–6 months is far more reliable than one at 8 weeks.
- Use the adult range, not the single number, when choosing a crate, harness or bed.
Frequently asked questions
- Which parent decides how big a mixed breed puppy gets?
- Neither parent decides it on their own. Most mixed breed puppies end up somewhere between the two parents’ weights, and males usually land nearer the top of that range. Puppies in the same litter can still differ a lot, especially in first-generation crosses.
- Can paw size tell me how big my puppy will get?
- Only roughly. Big paws often mean a big dog, but paw size varies between breeds and individual puppies. The parents’ weights and your puppy’s weight at a known age are much better guides.
- What if I don’t know the parents?
- Rescue puppies often come without parent information. Pick the size group you think fits (your vet or shelter can help) and treat the result as a rough range. Weigh your puppy every few weeks and recalculate: the estimate tightens as your puppy gets older. A dog DNA test can also suggest which breeds are in the mix.
- Do mixed breeds grow faster or slower than purebreds?
- Growth speed depends mainly on expected adult size, not on whether a dog is mixed. A small mix finishes growing at around 10–12 months; a large or giant mix can keep filling out until 18–24 months.
- How accurate is this for doodles?
- Doodles vary more than most dogs, because the Poodle parent can be toy, miniature or standard. If you know both parents’ adult weights, enter them: that narrows the range far more than the breed name does.
Breed growth guides
- Golden RetrieverGrowth chart and weight by age
- Labrador RetrieverGrowth chart and weight by age
- German ShepherdGrowth chart and weight by age
- French BulldogGrowth chart and weight by age
- Goldendoodle (Standard)Growth chart and weight by age
Estimates only, not veterinary advice. How the calculator works.