Puppy Weight Calculator
Predict your puppy's adult weight from its current age and weight.
Enter your values
ⓘ Live results
Results
- Predicted adult weight
- 13 kg (28.7 lb)
- Growth completed
- 62%
- Weight still to gain
- 5 kg
- Fully grown at
- about 13 months
- Likely adult range
- 11.1 - 15 kg
Working
- 18 kg / 0.615 growth fraction = 13 kg adult
| Age | Expected weight | % of adult |
|---|---|---|
| 2 months | 5.3 kg | 41% |
| 3 months | 6.8 kg | 53% |
| 4 months | 8 kg | 62% |
| 6 months | 9.6 kg | 74% |
| 8 months | 10.7 kg | 82% |
| 10 months | 11.4 kg | 88% |
| 12 months | 11.9 kg | 91% |
| 18 months | 12 kg | 93% |
Quick answer
Puppies reach a predictable fraction of adult weight at each age, and the fraction depends on breed size. Small breeds finish by 10 months, giant breeds take up to 24.
adult weight = current weight / growth fraction at this age
How to use the Puppy Weight Calculator
- 1Weigh your puppy and note its exact age in months.
- 2Pick the breed size band — for a mix, use the larger parent as a guide.
- 3Compare the monthly chart with real weigh-ins to see whether growth is on track.
Worked example
Using the values the calculator loads with:
Inputs
- Puppy age4 months
- Current weight8 kg
- Expected breed sizeMedium (11-25 kg)
Results
- Predicted adult weight13 kg (28.7 lb)
- Growth completed62%
- Weight still to gain5 kg
- Fully grown atabout 13 months
- Likely adult range11.1 - 15 kg
- 8 kg / 0.615 growth fraction = 13 kg adult
Frequently asked questions
How accurate is a puppy weight prediction?
Within about 15% for purebred puppies of a known size band. Mixed breeds vary more, especially when the parents differ in size.
Should I free feed a growing puppy?
No, particularly for large breeds. Overfeeding accelerates growth and raises the risk of hip and joint problems later.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.