⚖️ Puppy Weight Calculator: How Big Will My Puppy Get?
Pick the breed (or the size you expect), enter your puppy’s age in weeks and its weight today. You’ll get an estimated adult weight and how much growing is left.
3 months ≈ 13 weeks · 6 months ≈ 26 weeks
Bigger dogs grow for longer
Toy breeds are close to adult weight by about nine months; giant breeds keep growing until 18–24 months. So a 12-week-old puppy may already be 40% of its adult weight if it is small, but only 20–30% if it is a large breed. The calculator uses a growth curve for each size class and divides today’s weight by the expected share.
How accurate is it?
Treat the result as a range (±15%). Mixed breeds, sex and neutering age all shift the final size. The estimate gets better the older the puppy — re-check at four and six months.
Frequently asked questions
How can I tell how big my puppy will get?
The best guides are the parents’ sizes, the breed’s typical adult range and the puppy’s growth so far. A puppy’s weight at 4–6 months, compared with the typical growth curve for its size, gives a reasonable estimate.
When do puppies stop growing?
Small breeds around 9–10 months, medium breeds around 12 months, large breeds around 15 months and giant breeds at 18–24 months.
These calculators give general estimates for healthy pets. They are not veterinary advice — if your pet is unwell or has eaten something it shouldn’t, call your vet.
