Is one dog year really seven human years?

No — that's a myth. A 1-year-old dog is more like a 15-year-old human, and large dogs age faster than small ones after age two.

Pet Age Calculator

Convert your dog's or cat's age into human years — size-adjusted, not the old times-7 myth.

Pet's AgeyearsDog Size

Human-Year Equivalent

39 years

DNA-methylation formula estimate: ~57 years

Medium (21–50 lb) dogs age about 5 human years per dog year after age two. The old "multiply by 7" rule is a rough myth — pets mature fast early, then slow down.

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What Is the Pet Age Calculator?

The Pet Age Calculator converts dog and cat ages into human-equivalent years using modern veterinary guidelines: pets mature very quickly in their first two years, then age at a steadier rate that depends on size for dogs. It also shows the DNA-methylation research formula for comparison.

How It Works

Pick dog or cat, enter the age (and dog size), and see the human-year equivalent instantly.

When to Use It

Use it to understand your pet's life stage — puppy, adult or senior — and adjust care accordingly.

Frequently Asked Questions

Is one dog year really seven human years?: No — that's a myth. A 1-year-old dog is more like a 15-year-old human, and large dogs age faster than small ones after age two.

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