Dog Age Calculator

Convert a dog's age to human years, or human years to a dog's age, using the fit to Labrador retrievers from Wang et al. 2020. It is an estimate for Labradors, not a measure of an individual dog.

How it works

The source. Wang et al. 2020, Cell Systems 11(2), 176–185 (DOI 10.1016/j.cels.2020.06.006). The authors measured DNA methylation in blood samples and built an age clock from it. Their Figure 3D gives the relationship between a dog's age and a human age.

The formula. Dog to human: human years = 16 × ln(dog years) + 31, for dogs from 1 to 16 years. Human to dog: dog years = e^((human years − 31) ÷ 16), for human ages from 31 to about 75.4. Results are rounded to one decimal place, half up.

The data. The dog samples were 95 Labradors, after 9 of 104 were removed for low coverage. Dog ages ran from 0.1 to 16 years at the time of the blood draw. The human samples were 320 people aged 1 to 103.

The limits. This is a fit to Labradors, not a measure of an individual dog. The formula has no size or breed adjustment, so a Chihuahua or a Great Dane will not match it. It is not valid under one year, so no human age is given for a dog under 1. Dogs older than 16 are shown with a warning, because the fit does not cover them.