Lifestyle

Dog Age in Human Years

Convert your dog's age to human years using the epigenetic clock model.

The old "1 dog year = 7 human years" rule is scientifically inaccurate. A 2020 UC San Diego study mapped dog aging using epigenetic (DNA methylation) clocks and produced a more accurate logarithmic formula.

Enter your numbers

Dog's Age (years)

Results update as you change the inputs. Calculations run in your browser.

Human Age Equivalent

56.8 years

life Stage: Middle Age
old Rule: 35 years (old 7x rule — inaccurate)
note: Based on UC San Diego epigenetic research

See the formula

Formula and method

Human Age = 16 × ln(Dog Age) + 31

From the 2020 Trey Ideker lab paper at UC San Diego (Cell Systems journal). Methylation patterns in dog and human genomes are compared to determine biological age equivalence.

Worked examples

Puppy, 1 year old

Dog's Age (years):: 1

Human Age Equivalent: 31.0 years

Middle-aged dog, 7 years

Dog's Age (years):: 7

Human Age Equivalent: 62.1 years

Assumptions and limits

Based on Labrador retriever data from UC San Diego
Single breed formula; variations exist by size

This tool provides an educational estimate. Rules, rates and personal circumstances can change the answer. Review the assumptions before relying on a result. Report a correction.

Common mistakes to avoid

Using the 7x rule — dogs mature much faster in early years and then slow down.
Applying a single formula to all breeds — large breeds age faster and have shorter lifespans than small breeds.

Frequently asked questions

Is this formula accurate for all dogs?

The original study used Labrador retrievers. Other research suggests large breeds age faster and have shorter maximum lifespans than small breeds. The formula is a useful approximation for medium-sized dogs.

Why is the old 7-year rule wrong?

Dogs reach sexual maturity in about 1 year (equivalent to human adolescence at ~15 years), but humans take 15 years to reach the same point. Dogs also plateau in aging rate faster than humans in old age.