# Dog Age Calculator

> Convert your dog’s age to human-equivalent years using the AVMA chart for small or medium dogs or the 2020 epigenetic formula 16 ln(age) + 31.

Category: Everyday tools · Applies to: Worldwide · Last updated: 2026-10-29
Interactive calculator: https://calculators.geekmidst.com/calculators/dog-age-calculator

There is no single exact conversion. This calculator shows two published methods: the American Veterinary Medical Association chart, and the DNA-methylation formula of Wang et al. (2020).

Also called: Dog years calculator, Pet age equivalent calculator.

## Inputs
- Dog’s age: years (unit years; default 4)
- Months (unit months; default 0; optional)
- Method (options: AVMA chart: small dog (up to 20 lb / 9 kg), AVMA chart: medium dog (21–50 lb / 9.5–23 kg), Epigenetic clock: 16 × ln(age) + 31 (Wang et al. 2020); default avma_medium)

## Results
- Human-equivalent age
- Dog’s age in years
- Method

## Formula

```
AVMA chart (medium dog): 15, 24, 28, 32, 36, 42, 47, 51, 56, 60, 65, 69, 74, 78, 83, 87 at ages 1–16, interpolated between whole years;  Epigenetic: Human age = 16 × ln(Dog age) + 31
```

Where:
- ln: natural logarithm
- Dog age: in years

## Worked example
1. The AVMA chart gives 15 human years for year one, 24 by year two, then 28, and 32 at age 4.
2. For comparison, the epigenetic formula gives 16 × ln 4 + 31 = 16 × 1.386 + 31 = 53.2.

**Result:** A 4-year-old medium-sized dog is about 32 in human years on the AVMA chart, or about 53 by the epigenetic formula.

## What the result means

The methods disagree because they measure different things: the AVMA chart reflects typical life stage and lifespan, while the epigenetic clock compares DNA-methylation changes and suggests dogs age very fast when young. Neither is exact for an individual dog.

## Assumptions and limits
- The AVMA chart is used from 1 to 16 years, with straight-line interpolation between whole years.
- The epigenetic formula was derived from 104 Labrador retrievers.
- Large and giant breeds age faster than the charted sizes and are not covered by the AVMA chart here.
- Cats are not included because a full verified chart was not available.

## Questions

### Is one dog year equal to seven human years?

No. Both methods show dogs age much faster in their first two years and more slowly afterwards; the 7× rule is a myth.

### Which method should I use?

For life-stage care, the AVMA chart and your vet’s advice are the practical choice. The epigenetic formula is a research finding based on one breed.

## Sources
- [AVMA: Pets Age Faster (age chart)](https://ebusiness.avma.org/files/productdownloads/PetsAgeFasterPoster.pdf)
- [AVMA: Senior Pets (human equivalents by dog size)](https://ebusiness.avma.org/files/productdownloads/SeniorPets_En.pdf)
- [AKC: How to Calculate Dog Years to Human Years](https://www.akc.org/expert-advice/health/how-to-calculate-dog-years-to-human-years/)
- [Sci.News: report on Wang et al., Cell Systems 2020 (doi:10.1016/j.cels.2020.06.006)](https://www.sci.news/biology/dog-aging-08614.html)

## Related calculators
- [Age Calculator](https://calculators.geekmidst.com/calculators/age-calculator)
- [Pet Food Portion Calculator](https://calculators.geekmidst.com/calculators/pet-food-portion-calculator)
- [Pet Daily Water Need Calculator](https://calculators.geekmidst.com/calculators/pet-daily-water-need-calculator)

Source: GM¹X CalcVerse — https://calculators.geekmidst.com/calculators/dog-age-calculator