Dog Age Calculator
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Planning estimate only — not veterinary advice. Ask your veterinarian for health decisions. AAHA-style human-age chart by dog size — not the 7× myth.
Dog age
Human years (estimate)
37
5 dog years · medium size
- Chart source
- AAHA size class
Related calculators
Dog age in human years
Dogs age faster in early life and more slowly later — the simple “multiply by 7” rule is outdated. The American Animal Hospital Association publishes size-class charts: small (≤20 lb), medium (21–50 lb), large (51–90 lb), and giant (>90 lb) breeds age at different rates.
Year one maps to about 15 human years for all sizes; year two to about 24. After that, larger breeds accumulate “human years” faster than small breeds. This tool uses published chart values with interpolation for fractional ages.
Example: a 5-year-old medium dog ≈ 37 human years. A 5-year-old giant dog ≈ 42 human years.
Official sources
Rates and formulas in this calculator are based on the documentation below. Platforms change fees — confirm current numbers before pricing or payouts.
Common questions
Why not multiply by 7?
The 7× rule ignores breed size and the rapid early aging phase. AAHA and veterinary references use size-specific charts instead.
Is this a medical assessment?
No. It is a reference chart for curiosity and planning. Your vet determines life stage and care needs.