Cat Age Calculator (Cat Years)
Cat Age Calculator estimates your cat's age in human years. Cats age rapidly in their first two years and then more gradually. Indoor cats generally live longer.
Last updated: July 2026
A cat age calculator converts your cat's age to human years. The first year of a cat's life equals about 15 human years, the second year adds about 9, and each year after is roughly 4 human years. Indoor cats typically live longer than outdoor cats.
How to use Cat Age Calculator (Cat Years)
- Enter your cat's age in years.
- Optionally select whether your cat lives indoors, outdoors or both.
- Read the equivalent human age and life stage.
Frequently asked questions
How is cat age calculated?
First year = ~15 human years, second year = ~9, each subsequent year = ~4 human years.
Does lifestyle affect lifespan?
Yes — indoor cats typically live 12–18 years, while outdoor cats average 5–8 years due to greater risks.
Is my data stored?
No — the calculation runs entirely in your browser.
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