Dog Age Calculator
Convert your dog's age to the equivalent human age.
Enter your values and click Calculate
The popular rule of thumb that one dog year equals seven human years is a convenient but inaccurate simplification. Dogs mature from puppy to reproductive adult in roughly one year — a developmental stage that takes about 15 years in humans — yet a 10-year-old dog is not equivalent to a 70-year-old person. A 2020 Cell Systems study by researchers at UC San Diego found that methylation patterns in dog and human DNA follow a logarithmic relationship, suggesting dogs age very rapidly in early life and more slowly in middle and later years. This calculator implements that logarithmic formula to give a biologically grounded estimate of your dog's equivalent human age.
How It Works
Human Age = 16 × ln(dog age) + 31, where ln is the natural logarithm. This formula was derived from the 2020 Cell Systems paper by Tina Wang et al., which compared DNA methylation changes across the lifespans of Labrador Retrievers and humans. The logarithmic shape captures the fact that dogs age rapidly early in life — a 1-year-old dog reaches sexual maturity, comparable to a 15–20-year-old human — then age more slowly relative to humans in later years. The result is rounded to the nearest whole year. For ages at or below 0, the result is shown as 0 since ln(0) is undefined.