How to use this calculator
- Enter or choose method.
- Add a grade and credits for each course; leave unused rows blank.
- The human-equivalent age updates as you type. Use Copy result or Share to keep it.
Method
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
- ln
- natural logarithm
- Dog age
- in years
Worked example
- The AVMA chart gives 15 human years for year one, 24 by year two, then 28, and 32 at age 4.
- For comparison, the epigenetic formula gives 16 × ln 4 + 31 = 16 × 1.386 + 31 = 53.2.
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.