Cat Age Calculator
Convert your cat's age into human years, see which life stage they are in, and find out when senior care should start.
Cats age on the same schedule whatever their breed, so this only adds a link to that breed's weight chart.
Human-age equivalents are a well-established approximation, not a measurement, and lifespan figures are averages with very wide individual variation. Neither predicts anything about your own cat — ask your vet about their health.
Track your cat's weight in the free PetNoter app
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How cats actually age
The ×7 rule fails for cats at both ends. A one-year-old cat is fully sexually mature, close to adult size and perfectly capable of raising a litter. That is not a seven-year-old child — it is nearer a fifteen-year-old.
Feline ageing is front-loaded: about 15 human years in the first year, another 9 in the second, and then a steady four per year for the rest of their life. A two-year-old cat is roughly 24 in human terms; a twelve-year-old is around 64.
The one genuine difference from dogs is that size does not matter. In dogs a giant breed ages far faster than a toy one, which is why any honest dog calculator has to ask for the breed. Cats do not work that way — a Maine Coon and a Siamese arrive at the same human age together, even though one weighs three times what the other does. Breed changes how long a cat takes to finish growing, not how fast it ages.
You know the numbers. Now watch the trend.
A single weigh-in tells you very little — a chart of the last six months tells you everything. PetNoter keeps your cat's weight history in one place, free.
- Log a weigh-in in seconds and see the trend line
- Reminders for weigh-ins, vaccinations and vet visits
- Vet records, prescriptions and photos stored per pet
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Cat age chart: cat years to human years
Human-year equivalents at every age. The same figures apply to every breed.
| Cat's age | Human years | Life stage |
|---|---|---|
| 1 year | 15 | Young adult |
| 2 years | 24 | Young adult |
| 3 years | 28 | Young adult |
| 4 years | 32 | Young adult |
| 5 years | 36 | Young adult |
| 6 years | 40 | Young adult |
| 7 years | 44 | Mature adult |
| 8 years | 48 | Mature adult |
| 9 years | 52 | Mature adult |
| 10 years | 56 | Senior |
| 11 years | 60 | Senior |
| 12 years | 64 | Senior |
| 13 years | 68 | Senior |
| 14 years | 72 | Senior |
| 15 years | 76 | Senior |
| 16 years | 80 | Senior |
| 18 years | 88 | Senior |
| 20 years | 96 | Senior |
Life stages, and what changes at each
These follow the 2021 AAFP and AAHA feline life stage guidelines. The stage matters more than the number — it is what determines how often your cat should be seen.
| Stage | Age | What it means |
|---|---|---|
| Kitten | Up to 1 year | Rapid growth, vaccination course, neutering decision. |
| Young adult | 1–6 years | Peak condition. Annual check-up and a stable weight. |
| Mature adult | 7–10 years | Weight creeps up. Many vets move to twice-yearly visits. |
| Senior | 10+ years | Twice-yearly check-ups and routine bloodwork. |
Indoor cats typically live 12–18 years and many live well past twenty. That figure is a population average with very wide individual variation — it is here to show when senior care becomes worth starting, not to predict anything about your own cat.
Weight is the signal to watch in older cats
Cats hide illness extremely well, and in the mature and senior stages the scale usually moves before anything else does. Unexplained weight loss in particular is an early sign of hyperthyroidism, diabetes and kidney disease — three of the most common conditions in older cats, and all far more manageable when caught early.
A monthly weigh-in takes a minute and gives you a trend line. That trend is worth more than any single reading, and more than how your cat looks — a long coat hides a great deal.
Frequently Asked Questions
How do you convert cat years to human years?
A cat's first year is worth about 15 human years and the second adds about 9 more, putting a two-year-old cat at roughly 24. Every year after that adds about 4 human years. So a 10-year-old cat is around 56 and a 15-year-old is around 76.
Is one cat year seven human years?
No. The ×7 rule is wrong for cats in the same way it is wrong for dogs. A one-year-old cat is fully sexually mature and close to adult size, which is nothing like a seven-year-old child — it is much closer to a 15-year-old. Ageing is front-loaded in the first two years and then settles into a steady four human years per cat year.
Does breed change a cat's age in human years?
Barely. Unlike dogs, where a giant breed ages far faster than a toy one, cats age on roughly the same schedule whatever their breed — a Maine Coon and a Siamese are the same age in human years at ten. Breed affects how long a cat takes to reach full size, but not the rate at which it ages.
When is a cat considered senior?
Under the 2021 AAFP and AAHA life stage guidelines a cat is a kitten to one year, a young adult from one to six, a mature adult from seven to ten, and a senior from ten onwards. Many vets move to twice-yearly check-ups from seven rather than waiting for ten.
How old is my kitten in human years?
A one-month-old kitten is roughly a one-year-old child, three months is about four, six months about ten, and a one-year-old cat is around fifteen. Kittens gain roughly 100 g a week for the first six months, so weight is a useful cross-check on an estimated age.
How long do cats live?
Indoor cats typically live 12 to 18 years, and plenty live beyond twenty. Cats with outdoor access average considerably less, for reasons that have nothing to do with ageing — traffic, disease and injury. These are population averages with very wide individual variation.
More free tools
Track your cat's weight in the free PetNoter app
4.8 · Free · Android & iOS