How big will my puppy get?
Pick your puppy's size band (most owners know the parents' size or have a breeder estimate). Enter current age + weight. We project adult weight and show key growth milestones along the way.
Puppy growth calculator
Project your puppy's adult weight from current age + weight + size band. Growth curves are sourced from AAHA + Royal Canin breed-size growth standards.
Growth milestones
| Age | Estimated weight |
|---|
Puppy supplies worth having
Puppy-pads for the first 3–4 months, a puzzle feeder to slow down fast eaters and add mental stimulation.
- Frisco Training & Potty Pads (100-ct)$25–35Bulk pads for the first 3–4 months of housetraining.
- Outward Hound Nina Ottosson Puzzle$15–25Mental enrichment + slows down fast eaters. Good for puppies and bored adults.
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How puppies grow
Puppy growth isn't linear — it accelerates in the first 3–4 months, then slows dramatically. Smaller breeds finish growing faster (toy breeds reach adult weight around 9–10 months); giant breeds keep growing well past their first birthday (18–24 months for full muscle/skeletal maturity).
Size bands and adult-weight ranges
| Band | Adult weight | Mature at | Examples |
|---|---|---|---|
| Toy | 1.5–10 kg | ~10 mo | Chihuahua, Yorkie, Pomeranian |
| Small | 9–15 kg | ~12 mo | Beagle, French Bulldog, Cocker Spaniel |
| Medium | 15–25 kg | ~13 mo | Border Collie, Australian Shepherd |
| Large | 25–45 kg | ~16 mo | Labrador, Golden, German Shepherd |
| Giant | 45+ kg | ~22 mo | Great Dane, Mastiff, Saint Bernard |
The over-feeding trap (especially for large/giant breeds)
It's intuitive to feed a fast-growing puppy more food. For large and giant breeds, it's also dangerous. Excess calories accelerate growth in a way that increases the risk of developmental orthopedic disease (hip dysplasia, OCD, elbow dysplasia). Stick to the bag's puppy feeding chart for your projected adult weight, and aim for the *lean* end of normal body condition — slightly visible ribs is correct.
Sources: AAHA Canine Life Stage Guidelines (2019). Royal Canin growth standard charts. Hawthorne AJ et al., "Body-weight changes during growth in puppies of different breeds," J Nutr (2004).
Frequently asked questions
How accurate is this calculator?
Within roughly ±15% for typical-breed puppies in the right size band. Mixed-breed puppies have wider variance — paw size and parents' weight are the best predictors when the breed is unknown. Use this as a planning estimate, not a guarantee. Re-run every 2–4 weeks during rapid growth (under 6 months) for tighter projections.
What if I don't know my puppy's adult size?
For mixed-breed puppies, paw size is a rough proxy — big-pawed puppies generally become big dogs. Veterinarians often DNA-test or estimate from observable traits. The shelter or breeder usually has a best guess. When in doubt, pick the band that matches the "bigger parent" if you know one.
When should I switch from puppy food to adult food?
When the puppy is at ~90% of expected adult weight. For toy breeds that's 8–9 months; for giant breeds 14–18 months. Switching too early risks developmental issues (especially in large/giant breeds, where joint development extends beyond 18 months). Switching too late risks excess weight gain.
My puppy seems much smaller/bigger than the projection. Should I worry?
Maybe — see a vet. Common causes for unusually small puppies: parasites (very common), congenital portosystemic shunt, runt-of-litter syndrome. Common causes for unusually large puppies: over-feeding (most common), large-for-breed lineage. A vet can rule out the medical causes quickly with bloodwork and a physical.
How fast should my puppy gain weight?
Roughly: 1–4 lb per month for toy/small breeds; 3–8 lb per month for medium/large; 6–15 lb per month for giant. Faster than that suggests over-feeding (which causes orthopedic disease in large breeds). Slower than that warrants a vet check — especially in puppies under 4 months.