Dog Age Calculator
Convert your dog's age to human years — adjusted for breed size.
How the Dog Age Calculator Works
The old "1 dog year = 7 human years" rule is wildly inaccurate. Dogs mature very fast in their first two years, then aging slows. Larger breeds also age faster than smaller ones. This tool uses size-adjusted curves consistent with AAHA (American Animal Hospital Association) guidelines.
Roughly How It's Calculated
Year 1 ≈ 15 human years. Year 2 adds about 9 more. After that, each additional dog year adds 4–7 human years depending on size — small breeds age the slowest, giant breeds the fastest.
FAQ
Why do small dogs live longer?
Smaller dogs reach physical maturity later and their cells age more slowly relative to large breeds. Many toy breeds live 14–18 years; giant breeds often only 7–10.
Is the 7-year rule wrong?
Yes — it's a myth. Modern veterinary science shows aging is non-linear and breed-size dependent.
What's a "senior" dog?
Generally a dog in the last 25% of its expected lifespan. For giants that's age 6+; for small breeds it's 10+.
Does this work for puppies?
Yes — at 6 months a dog is roughly equivalent to a 10-year-old child.
Is my data stored?
No. The tool runs entirely in your browser.
Love using BreezyTools?
Go Pro for an ad-free experience, priority features, and support independent development — for less than a coffee a month.