Dog Age Calculator
Convert your dog's age to human years using the 2020 epigenetic-clock formula — not the outdated "×7" rule. Fast, free, and fully client-side.
Calculator Inputs
How the Dog Age Calculator Works
Estimates a dog's age in equivalent human years using a logarithmic formula derived from DNA methylation research, replacing the inaccurate "multiply by 7" rule of thumb still commonly cited. Most reliable for dogs 1 year and older — puppyhood ages under 1 year change too fast for any linear or logarithmic approximation to hold.
Formula
Human Age = 16 × ln(Dog Age in Years) + 31
Derived from a 2020 study comparing DNA methylation patterns between dogs and humans (published in Cell Systems), which found aging follows a logarithmic curve rather than a fixed yearly ratio — dogs age very fast early on and the rate slows with age.
Calculation Example
A 5-year-old dog: 16 × ln(5) + 31 ≈ 16 × 1.609 + 31 ≈ 56.7 human years.
Frequently Asked Questions
Why not just multiply dog years by 7?
That rule has no scientific basis and badly misrepresents both ends of a dog's life — it undercounts a young dog's early aging and overcounts an old dog's later years. The logarithmic formula matches actual biological aging markers.
Does breed size affect the result?
The formula was derived from Labrador Retrievers; small and giant breeds age at somewhat different rates (small breeds live longer, giant breeds age faster), so treat the result as a solid estimate, not exact for every breed.
Browse more
See all pet tools.