Convert your dog's age into human years using a breed-size-adjusted formula — more accurate than the old "1 year = 7 years" rule.
Dog Age Calculator
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Enter your dog's age in years (use decimals, e.g., 6 months = 0.5).
Select your dog's size category.
Click Calculate to see the equivalent human age and life stage.
The old "1 dog year = 7 human years" rule is inaccurate. Dogs mature fast in their first year (≈15 human years), slower in the second (+9), then about +4 to +7 human years per dog year depending on size — large and giant breeds age faster. This calculator uses the widely-cited AKC/University of Florida-styled size-based formula.
Larger breeds have shorter lifespans and age more rapidly after maturity. A Great Dane at age 6 is "older" in human-equivalent years than a Chihuahua of the same age.