Puppy Weight Estimator
How big will your puppy get? Estimate adult weight from current age and weight.
Estimate Adult Weight
How Puppy Growth Estimation Works
Puppies of different size classes grow on very different schedules. Small breeds reach half their adult weight around 11–12 weeks and finish growing by 9–10 months. Giant breeds hit the halfway mark closer to 20 weeks and may keep growing until age two. This estimator divides your puppy's current weight by the typical fraction of adult weight for its age and size class.
| Age | Small | Medium | Large | Giant |
|---|---|---|---|---|
| 8 weeks | ~30% | ~25% | ~20% | ~15% |
| 12 weeks | ~50% | ~40% | ~33% | ~25% |
| 16 weeks | ~65% | ~50% | ~45% | ~35% |
| 26 weeks (6 mo) | ~90% | ~75% | ~66% | ~55% |
| 52 weeks (1 yr) | 100% | ~98% | ~90% | ~80% |
These are population averages — individual genetics, diet, and neutering timing all shift the curve. Once your pup is grown, keep portions right with the dog calorie calculator and track their age in human years.
Frequently Asked Questions
How accurate are puppy weight estimates?
Expect a range rather than an exact number — estimates are usually within 10–20% for purebreds and less precise for mixed breeds. Knowing the parents' sizes is the best predictor of all.
When do puppies stop growing?
Small breeds by 9–10 months, medium by about a year, large breeds by 15–18 months, and giant breeds as late as 24 months.
What if I don't know my puppy's size class?
Look at the parents if possible, or ask your vet — paw size and growth-plate exams give good clues. When unsure between two classes, run the estimate for both to get a range.