Dog Age Calculator
Based on the 2020 UCSD epigenetic clock study, size-adjusted for Australian breeds. Far more accurate than the old "dog year = 7 human years" shortcut (which is only roughly right for a 4-year-old medium dog).
How the dog age formula works
In 2020, Tina Wang and colleagues at UCSD compared methylation patterns across dog and human DNA and found the actual biological ageing curve follows human_age ≈ 16 × ln(dog_age) + 31.
That means dogs age very quickly in the first two years (puppies are roughly equivalent to human teenagers at 1 year old), then slow dramatically. It's the opposite of the old "multiply by 7" rule.
Why size matters
Large and giant breeds age faster after maturity. A 10-year-old Great Dane is closer to human 85 than human 66. Small breeds age slightly slower. We add an offset after the first year based on published breed-size lifespan data.
When to step up vet visits
- Under 1 human-year equivalent: monthly wellness during puppyhood.
- Middle age (human 30–55): annual check + bloodwork from year 5.
- Senior (human 65+): 6-monthly check + bloodwork + urinalysis.
Not veterinary advice. Ageing estimates are based on published research and are approximate for individual dogs.