Age in Dog & Cat Years

Convert a human age into approximate dog years or cat years, using commonly cited veterinary rule-of-thumb formulas.

The "multiply by seven" rule for converting human years to dog years is one of the most widely repeated pieces of pet trivia that's also, according to veterinary researchers, fairly inaccurate — dogs age much faster in their first two years of life than the simple multiplier suggests, reaching rough physical and developmental maturity by around age two, and then aging more gradually afterward, which a flat seven-times multiplier doesn't capture at all.

More recent approximations, including the one used here, account for that uneven pattern instead of applying one constant rate across a dog's entire life — treating the first couple of years as a faster-aging period and slowing the rate after that, which more closely mirrors how veterinarians actually describe canine aging stages, even though any formula like this remains a rough approximation rather than a precise biological measurement.

Enter a human age, and this tool calculates the approximate equivalent in both dog years and cat years using these more nuanced, non-linear formulas rather than the oversimplified multiply-by-seven rule most people have heard. It's intended as a fun, roughly accurate estimate — actual aging varies considerably by breed, size, and individual animal, so treat the result as an approximation, not a veterinary assessment.

1. Enter an age in human years.
2. Press Convert.
3. See the approximate dog-year and cat-year equivalents.