Cat Age Calculator
Convert your cat's age to human years using the standard veterinary age chart. Fast, free, and fully client-side.
Calculator Inputs
How the Cat Age Calculator Works
Converts a cat's age to its human-year equivalent using the age brackets commonly published by veterinary and cat-welfare organizations — a cat ages very fast in its first two years, then roughly 4 human years per additional cat year.
Formula
Year 1 = 15 human years · Year 2 = +9 (24 total) · Each year after = +4 human years
A cat reaches rough physical and behavioral maturity by its second birthday (≈24 human years), then ages at a much steadier rate afterward.
Calculation Example
A 6-year-old cat: 24 (through year 2) + 4×4 (years 3–6) = 40 human years.
Frequently Asked Questions
Is this the same for indoor and outdoor cats?
The chart reflects average lifespan data; indoor cats often live longer and may age more slowly in practice, but there is no separate widely-published indoor/outdoor formula.
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