How old is your dog or cat in human years? Select your pet, enter their age, and get an instant science-based conversion.
Step 1 — Choose your pet
Step 2 — Dog size
Enter age in years. You can use decimals (e.g. 1.5 for 18 months).
Please select a pet type and enter a valid age.
Human Age Equivalent
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human years
💡 Did you know? The classic "multiply by 7" rule is a myth. A dog's first year equals roughly 15 human years — because they mature from puppy to adult very rapidly. The conversion slows significantly after year 2.
How the conversion works
1
Year 1 = 15 human years. Pets mature extremely fast in their first year — reaching full sexual maturity and adult size.
2
Year 2 = +9 human years. The second year adds another major developmental leap — equivalent to a young adult.
3
Each additional year = +4–5 human years (varies by dog size — large dogs age faster). Cats are relatively consistent after year 2.
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