How to use this cat age calculator
Enter your cat's age in years and any extra months. The calculator converts it to human years using the chart published by International Cat Care and endorsed by the American Association of Feline Practitioners (AAFP), then shows your cat's life stage and when the next stage starts.
How cat years compare to human years
Cats grow up very quickly. By the end of their first year, they're roughly equal to a 15-year-old person, and at two they're about 24. After that, each cat year adds about four human years. The formula for cats over two is simple:
Human years = 24 + (cat's age − 2) × 4
Worked example: a 10-year-old cat is 24 + (10 − 2) × 4 = 24 + 32 = 56 in human years. A 15-year-old cat is 24 + 52 = 76.
Cat years to human years chart
| Cat's age | Human years | Life stage |
|---|---|---|
| 1 month | 1 | Kitten |
| 3 months | 4 | Kitten |
| 6 months | 10 | Kitten |
| 1 year | 15 | Young adult |
| 2 years | 24 | Young adult |
| 3 years | 28 | Young adult |
| 5 years | 36 | Young adult |
| 7 years | 44 | Mature adult |
| 10 years | 56 | Mature adult |
| 11 years | 60 | Senior |
| 13 years | 68 | Senior |
| 15 years | 76 | Senior |
| 18 years | 88 | Senior |
| 20 years | 96 | Senior |
| 25 years | 116 | Senior |
Cat life stages
The 2021 AAHA/AAFP Feline Life Stage Guidelines group cats into four stages:
- Kitten (birth to 1 year): rapid growth, vaccinations, neutering and learning to accept handling.
- Young adult (1 to 6 years): fully grown. The focus is on keeping a healthy weight and teeth.
- Mature adult (7 to 10 years): roughly 44 to 56 in human years. Weight gain and dental disease become more common.
- Senior (over 10 years): kidney disease, an overactive thyroid, arthritis and diabetes become more likely. Twice-yearly checkups help catch them early.
How long do cats live?
Indoor cats commonly live 12 to 18 years, and many reach their 20s. Cats that roam outdoors face traffic, fights, infectious diseases and predators, and on average live shorter lives. Keeping your cat at a healthy weight, looking after its teeth and taking it for regular checkups are the simplest ways to add healthy years.
Signs your cat is getting older
- Sleeping more and jumping less, often because of arthritis, which cats hide well.
- Drinking and urinating more, which can be an early sign of kidney disease or diabetes.
- Losing weight despite a good appetite, a classic sign of an overactive thyroid.
- Grooming less, so the coat looks greasy or matted, especially along the back.
- Changes in behavior, such as night-time crying or using places other than the litter box.
None of these is "just old age" until a vet has checked. Many of them are very treatable.
Frequently asked questions
How old is a 1-year-old cat in human years?
About 15. In its first year a cat goes from a newborn to a sexually mature adolescent, which takes people about 15 years.
Is one cat year equal to seven human years?
No. The seven-year rule is a myth. Cats age much faster at first (about 15 years in the first year and 9 in the second) and then about 4 human years per cat year.
What age is a senior cat?
Under the AAHA/AAFP guidelines, cats are seniors from about 11 years old, roughly 60 in human years. Many vets start senior blood tests at around this age.
How old is the oldest cat?
The oldest cat on record, Creme Puff from Texas, lived to 38 years and 3 days, according to Guinness World Records. That is over 160 in human years by the standard chart.
How can I tell how old my cat is?
A vet can estimate age from the teeth (adult teeth are in by about 6 months, and tartar and wear increase with age), the eyes, the coat and muscle tone. For adult cats, the estimate is usually a range of a few years.
Human-year values are estimates for comparison only. Every cat ages differently depending on genetics, lifestyle and health.