How big will my puppy get?
Short answer
Divide your puppy’s weight by the share of adult weight it has usually reached at its age. A 6-month-old medium-size puppy is typically at about 66 percent of its adult weight, so a 20-pound puppy would reach roughly 30 pounds, according to the AKC chart. The estimator below does the sum. It is approximate and covers puppies from 6 to 18 months.
Key takeaways
- Adult weight is estimated as weight now divided by the share of adult weight at that age, from the AKC chart.
- Pick the size group your puppy is expected to be, or choose “Not sure” to see all four estimates.
- The AKC chart starts at 6 months, so we show no estimate for younger puppies.
- The result is a guide. Individual puppies vary.
How do I estimate my puppy’s adult weight?
Use the AKC chart of the share of adult weight reached at each age. Divide your puppy’s current weight by that share. For example, a puppy in the medium group is about 66 percent grown at 6 months, so a 20-pound puppy has about 20 ÷ 0.66, or roughly 30 pounds, left to reach (our calculation).
| Age | Small0 to 20 lb as an adult | Medium21 to 50 lb as an adult | Large51 to 100 lb as an adult | Extra-largeover 100 lb as an adult |
|---|---|---|---|---|
| 6 months | 75% | 66% | 60% | 50% |
| 9 months | 90% | 85% | 75% | 65% |
| 12 months | 100% | 95% | 85% | 80% |
| 15 months | 100% | 100% | 95% | 90% |
| 18 months | 100% | 100% | 100% | 100% |
Which size group should I choose?
The AKC defines the groups by adult weight: small (0 to 20 lb), medium (21 to 50 lb), large (51 to 100 lb), extra-large (over 100 lb). If you do not know, choose “Not sure”. The estimator then shows four estimates; the right one is the group whose weight range contains its own estimate. When you choose a group, the estimator also warns you if the result falls outside that group’s range.
How accurate is the estimate?
The AKC states that its numbers are approximate, and we draw a straight line between the listed ages, which is our own assumption. Mixed breeds and puppies that grew unevenly can differ. For a firm answer, ask your veterinarian to track your puppy against a growth curve.
What if my puppy is under 6 months?
The AKC chart starts at 6 months, so we do not give a number for a younger puppy. Ask your veterinarian or the breeder, who may know the parents’ sizes. You can still use the puppy feeding calculator for daily food.
Frequently asked questions
How big will a 6-month-old puppy get?
Divide its weight by the share of adult weight for its size group: about 75 percent for small, 66 for medium, 60 for large and 50 for extra-large, per the AKC chart. A 20-pound medium puppy comes to roughly 30 pounds.
Can I estimate adult size for a puppy under 6 months?
Not with this chart, which starts at 6 months. Ask your veterinarian or breeder.
Why does the estimator ask for a size group?
The share of adult weight at a given age is different for small and large puppies, so the chart is split by size group.
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