Dog age calculator
Your dog’s age,
in human years.
Forget multiplying by seven. Enter your dog’s birth date and adult size, and EPOCH estimates their human-equivalent age using the size-adjusted method vets actually use — fast ageing early on, then a gentler, breed-dependent climb.
0human years (approx.)—
- actual age
- 0
- in dog-days lived
- 0
An estimate. Real ageing varies with breed, genetics and health — your vet is the better judge.
Why “times seven” gets it wrong
A one-year-old dog is nothing like a seven-year-old child — it is closer to a teenager, well past puberty. Dogs front-load their ageing, then slow down, and the slowdown differs by size. A flat multiplier can’t capture any of that, which is why this tool treats the early years and later years separately and asks for breed size.
The result is a friendly estimate, not a medical reading. For anything health-related, your vet — who knows the breed, weight and history — is the real authority. Curious about the human version of the same question? See our honest note on biological age.
Frequently asked questions
Is one dog year really seven human years?
No — that rule is a myth. Dogs mature fast in their first two years (the first ≈ 15 human years, the second adds ≈ 9) and then age more slowly, at a rate that depends on their size. This calculator follows that size-adjusted approach.
How is dog age converted to human years here?
Year one counts as about 15 human years and year two reaches about 24. After that, each dog-year adds roughly 4 human years for small breeds and up to 7 for giant breeds, since larger dogs age faster.
Why does size change the result?
Small dogs tend to live longer and age more gradually in later life, while giant breeds reach senior age sooner. Selecting the adult size adjusts the later-life conversion to match.
Is there a scientific formula for dog age?
A 2020 study (Wang et al., Cell Systems) proposed human age ≈ 16 × ln(dog age) + 31 from DNA methylation in Labradors. It is elegant but breed-specific; the size-adjusted method used here is the practical estimate vets favour. Either way, treat the number as an approximation.