Dog Years: How to Calculate Dog Age

Use this free dog years: how to calculate dog age to convert dog age to human years with a size-based rule and the 2020 epigenetic formula.

How the dog years: how to calculate dog age works

Size-based: 15 years for year one, 9 for year two, then 4–7 per year by size. Epigenetic: human age ≈ 16 × ln(dog age) + 31.

Frequently asked questions

Why two methods?

They come from different approaches; the size-based rule is practical and the epigenetic formula comes from a Labrador study.

Results are estimates for general information only. They are not a substitute for professional advice where applicable. Found a mistake? Report an error.