Free Puppy Weight Calculator
This puppy weight calculator estimates your puppy's adult weight from its weight and age now. The answer updates as you type.
Puppy growth chart: share of adult weight by age
| Age | Small | Medium | Large | Giant |
|---|---|---|---|---|
| 8 weeks | 25% | 20% | 16% | 13% |
| 12 weeks | 40% | 33% | 28% | 22% |
| 16 weeks | 55% | 47% | 40% | 32% |
| 20 weeks | 68% | 60% | 52% | 42% |
| 6 months | 82% | 74% | 66% | 55% |
| 8 months | 95% | 90% | 82% | 70% |
| 12 months | 100% | 98% | 95% | 86% |
| 18 months | 100% | 100% | 100% | 96% |
| 24 months | 100% | 100% | 100% | 100% |
Puppy weight chart: example puppies
Expected weight at each age for a puppy that will reach a typical adult weight in its size class.
| Age | Small (10 lb adult) | Medium (40 lb adult) | Large (70 lb adult) | Giant (120 lb adult) |
|---|---|---|---|---|
| 8 weeks | 3 lb | 8 lb | 11 lb | 16 lb |
| 12 weeks | 4 lb | 13 lb | 20 lb | 26 lb |
| 16 weeks | 6 lb | 19 lb | 28 lb | 38 lb |
| 20 weeks | 7 lb | 24 lb | 36 lb | 50 lb |
| 6 months | 8 lb | 30 lb | 46 lb | 66 lb |
| 8 months | 10 lb | 36 lb | 57 lb | 84 lb |
| 12 months | 10 lb | 39 lb | 67 lb | 103 lb |
| 18 months | 10 lb | 40 lb | 70 lb | 115 lb |
| 24 months | 10 lb | 40 lb | 70 lb | 120 lb |
How the puppy weight calculator works
- Adult weight ≈ weight now ÷ share of adult weight reached at this age (chart above).
- "Not sure" picks the size class from the estimate itself, then re-checks it.
- The range shown is ±15%, because individual puppies grow at different rates.
The growth shares are rounded estimates that follow published puppy growth curves. Feeding a growing puppy? Use the dog food calculator (puppy settings), and see the dog age calculator for age in human years.
Frequently asked questions
How does the puppy weight calculator work?
Puppies of each size reach a fairly predictable share of their adult weight by a given age. The puppy weight calculator divides your puppy's weight now by that share. For example, a medium puppy at 12 weeks is about a third of its adult weight.
How big will my puppy get?
Use the estimate as a guide, not a promise. The parents' size, especially the mother's, is a good cross-check, and paw size is a poor predictor.
When do puppies stop growing?
Small breeds finish growing at about 9 to 12 months, medium breeds at 12 to 15, large breeds at 15 to 18, and giant breeds as late as 18 to 24 months.
Is this the same as a dog weight calculator?
This tool predicts adult weight for a growing puppy. For an adult dog, the dog food calculator works out daily calories for its current or ideal weight.
Is my puppy underweight or overweight?
Weight alone cannot tell you. Vets use a body condition score: you should feel the ribs easily under a thin layer of fat and see a waist from above.