Convert your dog's age to human years. The first year of a dog's life equals approximately 15 human years.
The old rule of "1 dog year = 7 human years" isn't accurate. Dogs age much faster in their first two years. The accepted formula uses: 15 human years for the first year, plus about 9 years for year two, and then approximately 4-5 years per additional dog year depending on size. Smaller breeds tend to live longer and age more slowly than larger breeds.