Cat Age Calculator
Convert your cat's age to human years
In their prime and settled
📊 Based on the feline life-stage guidelines from the AAFP and AVMA
How cat years work (forget “times 7”)
The old “one cat year equals seven human years” rule is a myth. Cats do most of their growing up in the first two years and then age more gradually. The feline life-stage guidelines from the American Association of Feline Practitioners and the AVMA use this approach instead, and it is what the calculator above runs on:
- Year 1 is about 15 human years. A one-year-old cat is already a teenager.
- Year 2 adds about 9 more, so a two-year-old cat is roughly 24.
- Every year after that adds about 4. Cats age at a similar rate regardless of size, so a sphynx and a maine coon track the same.
Cat years to human years chart
A quick reference for converting cat years to human years. Use the calculator above for any age in between.
| Cat's age | Human years | Life stage |
|---|---|---|
| 1 year | 15 | Junior |
| 2 years | 24 | Junior |
| 3 years | 28 | Prime Adult |
| 4 years | 32 | Prime Adult |
| 5 years | 36 | Prime Adult |
| 7 years | 44 | Mature |
| 10 years | 56 | Mature |
| 12 years | 64 | Senior |
| 15 years | 76 | Geriatric |
| 18 years | 88 | Geriatric |
| 20 years | 96 | Geriatric |
Human-age equivalents are estimates. Aging varies by genetics, weight, and health.
Kitten in human years: the first year
Kittens age fastest of all. A few rough checkpoints owners ask about:
- 3 months is loosely like a 4-year-old child — playful and into everything.
- 6 months is around a 10-year-old, and most kittens are spayed or neutered around now.
- 12 months lands at about 15 in human years — a full-blown teenager.
Just adopted a kitten? Our new kitten checklist covers the first-year setup, vet timeline, and supplies.
How long do cats live?
Indoor cats commonly live 12 to 18 years, and plenty reach their early 20s. Outdoor and indoor-outdoor cats live far shorter lives — often just 3 to 5 years — because of traffic, predators, fights that spread disease, and exposure.
Keeping a cat indoors is the single biggest factor in how long it lives. For the full picture, including the coyote and winter risks specific to Canada, see our guide on indoor vs outdoor cats.
How to tell how old a rescue cat is
Many adopted cats arrive with an estimated age and no paperwork. A vet can place a cat's age from a few clues: the teeth (kittens have all their adult teeth by about 6 months; tartar and wear build up with age), the coat (older cats often have a coarser coat and groom less), the eyes (the iris looks more textured and the lens slightly cloudy with age), and overall muscle tone.
Once you have a vet's estimate, the calculator above turns it into a human-age equivalent. Browse adoptable rescue cats of every age across Canada.
Frequently asked questions
Is one cat year really seven human years?
No. The “times 7” rule is a myth for cats just as it is for dogs. Cats mature very quickly at first: a 1-year-old cat is roughly a 15-year-old human, and a 2-year-old cat is about 24. After that, each cat year adds about 4 human years. Unlike dogs, cats age at a similar rate regardless of size, so the calculator above does not need a size input.
How old is my cat in human years?
Enter your cat’s age in the calculator above for an exact number. As a quick guide: year 1 is about 15 human years, year 2 brings the total to about 24, and every year after that adds roughly 4. So a 5-year-old cat is about 36 in human years, a 10-year-old cat is about 56, and a 15-year-old cat is about 76.
How long do cats live?
Indoor cats commonly live 12 to 18 years, and many reach their early 20s. Outdoor and indoor-outdoor cats live far shorter lives, often just 3 to 5 years, because of traffic, predators like coyotes, fights, and disease. Keeping a cat indoors is the single biggest thing you can do for its lifespan, along with a healthy weight, dental care, and regular vet visits.
When is a cat considered a senior?
Vets generally consider cats mature at 7 to 10 years, senior at 11 to 14, and geriatric at 15 and up. Senior cats benefit from twice-yearly checkups, bloodwork to catch kidney and thyroid changes early, easy access to litter and food, and warm, quiet sleeping spots. Many cats stay active well into their senior years with the right care.
How can I tell how old a rescue cat is?
A vet estimates a cat’s age from its teeth (kittens get adult teeth by about 6 months; tartar and wear increase with age), the condition of the coat (older cats may have a coarser or less groomed coat), the eyes (the iris can look more textured and the lens slightly cloudy with age), and overall muscle tone. None is exact, but together they usually place a cat within a few years. Many rescue cats are listed with an approximate age for this reason.
Do indoor cats live longer than outdoor cats?
Dramatically longer. Indoor cats average 12 to 18 years while strictly outdoor cats often live only 3 to 5. The difference is not the indoors itself but everything avoided outdoors: vehicle traffic, predators, cat fights that spread FIV and FeLV, parasites, poisons, and extreme weather. This is why nearly every cat rescue requires an indoor-only adoption commitment.