Cat Age Calculator

Convert your cat's age into human years using the standard veterinary chart: 15 human years for the first year, 24 by the second, and four more for every year after that.

Cats pack a lot of growing up into their first couple of years, then settle into a steadier pace. The widely used veterinary chart counts a cat's first year as about 15 human years, the second year brings the total to 24, and each year after adds roughly four human years. Unlike dogs, cat aging doesn't vary much by breed or size, so a single chart works well for most cats. This calculator applies that chart to your cat's age.

How cat years convert to human years

The first two years count for a lot; after that it's a steady four human years per calendar year.

Year 1 = 15 human years
Year 2 = +9 (24 total at age 2)
Each year after = +4 human years
Cat ageHuman ageLife stage
1 year15Junior
2 years24Young adult
7 years44Mature
11 years60Senior
15 years76Super-senior

Worked example

A 7-year-old cat:

Years 1–224
5 more years × 420
Human-age equivalent≈ 44 years

Cat life stages

Vets group cats into life stages: kitten and junior up to about two years, prime and mature through the middle years, senior from around eleven, and super-senior past fifteen. Knowing the stage helps you adjust diet, activity and check-up frequency — senior cats benefit from twice-yearly vet visits to catch issues like kidney disease and arthritis early. Indoor cats commonly reach their late teens, and some pass twenty.

Frequently asked questions

How old is my cat in human years?
Enter your cat's age and the calculator applies the standard chart: 15 for year one, 24 by year two, then four per year after.
Does breed change a cat's age conversion?
Not much. Unlike dogs, cats age at a similar rate regardless of breed or size, so one chart works for most cats.
When is a cat a senior?
Around 11 human-equivalent years and up. Cats over 15 are often called super-seniors and need extra monitoring.
How long do cats live?
Indoor cats commonly live 13–17 years, and many reach their late teens or early twenties with good care.

Related calculators

A general estimate using the common veterinary chart, not veterinary advice. Individual cats vary with health, breed and lifestyle — consult your vet about your cat's life stage and care.
Written by the CalcPine team · Reviewed for accuracy · Last updated 13 July 2026 · Method: 15 years (year 1) + 9 (year 2) + 4 per later year.