Free & private

Dog Age Calculator

Convert your dog's age to human years using the 2020 epigenetic aging formula, alongside a size-adjusted traditional estimate for comparison.

Your dog's details

Age can include decimals, like 1.5 or 7.5 years.

years
🐾Your result will appear hereAdd your dog's age and size, then select calculate.
Human age equivalent (epigenetic formula)
0yrs
0Traditional estimate
0Difference
Dog ageMedium breed

The epigenetic formula (16×ln(age)+31) is based on 2020 DNA methylation research and reflects rapid early aging that slows with age. The traditional table is a widely published, size-adjusted rule of thumb. Neither replaces veterinary guidance.

How to use the dog age calculator

Enter your dog's age in years — decimals are fine — and choose their adult size category, then select calculate. Everything runs locally in your browser, so nothing is uploaded or stored by this tool.

1. Enter dog's age

Use their current age in years, including decimals for puppies.

2. Choose adult size

Pick small, medium, large or giant based on adult weight.

3. Compare both methods

See the epigenetic estimate alongside the traditional size-adjusted table.

Understanding the two aging methods

The old "multiply by 7" rule doesn't reflect how dogs actually age — they mature very quickly in their first couple of years, then age more gradually. This calculator uses a newer epigenetic formula alongside a traditional size-adjusted table so you can compare both.

Epigenetic formula

Human age = 16 × ln(dog age) + 31, based on comparing DNA methylation "clocks" in dogs and humans.

Traditional method

A published multiplier table adjusted for adult size, since breed size affects aging speed and lifespan.

Why they differ

The epigenetic formula treats aging as a smooth biological curve, while the traditional table uses fixed breakpoints by size.

How does the epigenetic dog age formula work?

It uses human age = 16 × ln(dog age) + 31, based on 2020 research comparing DNA methylation patterns in dogs and humans, showing dogs age very fast early in life and more slowly later, unlike the old 7-year rule.

What is the traditional dog-year method?

It is a simpler, widely published multiplier table adjusted by adult breed size, since larger breeds tend to age faster once they reach adulthood.

Why do small and giant breeds age differently?

Giant breeds generally have shorter lifespans and age faster biologically in adulthood, while small breeds tend to age more slowly after their first couple of years.

Which method should I trust more?

The epigenetic formula is grounded in biological aging research, while the traditional table is a well-known rule of thumb. Neither replaces an assessment from your veterinarian.

Try another free calculator: Age Calculator, Pregnancy Due Date Calculator, or Bucket List Tracker. Browse all online tools.