Dog Age Calculator — Dog Years to Human Years
Convert your dog’s age to human years using a size-adjusted model and the 2019 epigenetic-clock formula. Free, in your browser.
🔒 Calculated in your browser. Two common models — a size-adjusted AVMA-style estimate and the 2019 epigenetic-clock formula. Approximations, not veterinary advice.
Your dog’s age in human years
The old "multiply by 7" rule is a myth — dogs mature fast early on, then age more slowly, and larger breeds age quicker. Enter your dog’s age and size and the tool gives a size-adjusted estimate (first year ≈ 15, second ≈ +9, then per-year by size) alongside the 2019 epigenetic-clock formula (16 × ln(age) + 31).
Two models, both estimates
The size-adjusted model is the familiar vet-style guide; the epigenetic formula comes from a DNA-methylation study on Labradors and skews older for young dogs. Both are approximations — real ageing varies by breed and health. Everything runs in your browser.
Frequently asked questions
Is one dog year seven human years?
No — that’s a myth. A dog’s first year is roughly 15 human years and the second about 9 more, then it slows and depends on size.
Why do bigger dogs age faster?
Larger breeds have shorter lifespans and reach "senior" age sooner, so the tool adds more human years per dog year for large dogs than small ones.