Dog Age Calculator
See your dog’s age in human years, adjusted for adult size.
Dog age and size
A dog’s aging rate after age 2 depends on its adult size — enter your dog’s weight, or pick a size category directly.
About 39 human years (Medium (21–50 lb))
This is a guideline approximation based on published veterinary aging guidance, not an exact measurement for your individual dog — see the life stage reference chart for the underlying figures and sources, and check with your vet for anything health-related.
Frequently asked questions
- Why does size matter for dogs but not just breed?
- Adult body size is the strongest predictor of aging rate and lifespan across breeds — larger dogs mature faster as puppies but age faster and live shorter lives as adults, while smaller dogs age more slowly after maturity and tend to live longer.
- Is "multiply dog years by 7" accurate?
- No — AVMA and AAHA both describe a front-loaded curve instead: about 15 human years for year 1, 9 more for year 2 (24 total), then a slower rate after that. The exact per-year rate after age 2 isn't identical across every veterinary source — AVMA and AAHA's own published figures differ slightly for the same size dog — so this calculator uses a commonly cited size-scaled convention rather than one single guideline's verbatim table.
- What if I don't know my dog's exact adult weight?
- Switch to "By size category" and pick the closest match — small (toy/small breeds), medium, large, or giant. The category matters more than the exact pound figure.