Dog Age Calculator

Convert your dog’s age to human years using the 2020 epigenetic formula or the size-adjusted classic method.

Understanding the dog age calculation

The old rule of multiplying by seven was never accurate. Dogs mature far faster in their first two years and then age more slowly, and larger breeds age faster than small ones throughout.

A 2020 study comparing DNA methylation in dogs and humans produced a logarithmic formula that matches the biology much more closely, particularly for young dogs. Both methods are shown so you can compare.

Try it with these numbers

Take the starting scenario, a method of Epigenetic formula (2020 research). That gives a human age equivalent of 56.8. Underneath, Epigenetic estimate comes out at 56.8 human years and Size-adjusted estimate at 39 human years. Change any field and every figure updates as you type.

Getting your answer

  1. Enter your dog’s age in years.
  2. Select the size category.
  3. Choose the epigenetic or size-adjusted method.

Formula reference

epigenetic: human age = 16 ร— ln(dog age) + 31 size method: 15 for year one, 9 for year two, then 4โ€“7 per year by size

Questions people ask about this

Why is the seven-year rule wrong?
It assumes a constant ratio. In reality a one-year-old dog is roughly equivalent to a human teenager, not a seven-year-old child.
Why do big dogs age faster?
Larger breeds grow faster and have shorter lifespans. The mechanism is not fully settled but the pattern is consistent.
Which method should I use?
The epigenetic formula is better supported for dogs over one year; the size method is more intuitive for older dogs of known breed size.