Cat Age Calculator: Cat Years to Human Years

How human age is calculated

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The calculator converts cat years to human years with the cat age chart from the Feline Veterinary Medical Association (FelineVMA). The chart sets fixed points for the first two years: a cat of 1 month is 1 in human years, 3 months is 4, 6 months is 10, 1 year is 15 and 2 years is 24. From then on, every cat year adds 4 human years.

The chart cites no study behind its numbers. It is a professional convention, not a measurement.

Between the fixed points, the calculator draws a straight line. That interpolation is our choice, not FelineVMA's. A cat of 9 months, for example, comes out at 12.5. The calculator counts completed years, the way we give our own age, so it shows 12.

The four life stages

The life stage follows the Feline Life Stage Guidelines from the American Animal Hospital Association and the American Association of Feline Practitioners (AAHA/AAFP, 2021). They divide a cat's life into four stages:

• Kittenunder 1 year
• Young adult1–6 years
• Mature adult7–10 years
• Senior11 years and older

The guidelines themselves say the boundaries are arbitrary divisions of a continuum. A cat does not change overnight on its birthday.

The calculator counts whole years, so a cat of 10 years and 11 months is still a mature adult, and the senior stage starts at 11 years. Ask your vet what your cat's life stage means for its care and check-ups.

Life expectancy: what the number means

The life expectancy figures build on a study by Teng and colleagues (2024) of 7,936 cats under primary veterinary care in the UK that had died, with records from VetCompass. Across all of them, life expectancy at birth was 11.74 years.

The authors have published their data for each cat as open data. The figures in the calculator are calculated by us from that data, not published by the authors.

For a cat of a given age, the calculator looks only at the cats in the data that lived at least that long. Among them, it works out how much sex, neutering and breed shifted the age they reached, with the three factors adjusted for each other. If you answer «don't know», that factor is left out, and your cat counts as average for it.

The result shows the average age that cats with your cat's profile reached, the range that half of them reached, the chance of reaching 15 and 20 years, and how much each answer adds or takes away. Because only cats that lived at least as long as yours are counted, the average for an older cat is higher than the 11.74 years at birth.

Life expectancy is shown only where at least 300 cats in the data reached your cat's age. With this data, that is up to 20 years and 1 month.

These are averages for cats with the same age, sex, neutering status and breed, never a prediction for your cat. Individual cats vary a lot, and health, care and heredity matter more than anything the calculator can see. Your vet is the one who can assess your cat.

What affects how long cats live

The study compared cats by sex, neutering and breed. Unless we say otherwise, the figures below are the study's own.

Sex

Females had a life expectancy at birth of 12.51 years and males 11.18 years. That compares the two groups as they are. With neutering and breed taken into account, males that died after 9 months lived 1.20 years shorter than females.

Neutering

With sex and breed taken into account, neutered cats that died after 9 months lived 1.07 years longer than entire cats. Entire cats also had 4.29 times the odds of dying before 3 years of age.

Breed

Crossbred cats had a life expectancy at birth of 11.89 years and purebred cats 10.41 years. With sex and neutering taken into account, purebred cats that died after 9 months lived 1.27 years shorter, and they had 1.83 times the odds of dying before 3 years of age.

Among single breeds, Burmese (14.42 years) and Birman (14.39 years) had the longest life expectancy at birth, and Sphynx the shortest (6.68 years), though that figure rests on only 18 cats. The calculator asks only whether your cat is mixed breed or purebred, not which breed.

The older the cat, the less these factors matter

The study's figures above apply to cats that died after 9 months. For a cat that is already older, the same factors make a smaller difference. The table shows how much each factor shifted the average age reached among the cats that had reached a given age.

Male is compared with female, neutered with entire, and purebred with crossbred, with the three factors adjusted for each other. Our method differs from the study's, so the numbers do not match its own figures exactly. Values close to zero, whichever sign they have, mean the factor makes little difference at that age.

Weight

The cats in the study had a median adult weight of 5.5 kg. The authors read their results, together with studies from Australia and the US, as a sign that being mildly overweight is linked to a longer life. That is their interpretation, and the calculator does not ask about weight.

Indoors or outdoors

The study did not record whether cats lived indoors or went outside, so there are no figures for it here, and the calculator does not ask. The authors point out that outdoor access brings a risk of accidents, fights and infection.

Frequently asked questions

How long do cats live?

In the UK study behind our figures, cats had a life expectancy at birth of 11.74 years: 12.51 years for females and 11.18 for males. That is an average, and individual cats vary a lot. For the average among cats with the same age, sex, neutering status and breed as yours, use the calculator above.

How old is my cat in human years?

Enter your cat's age in years and months in the calculator above. By the FelineVMA chart, a cat of 1 year is 15 in human years and a cat of 2 years is 24. After that, each year adds 4, so a cat of 10 years is 56. The table above lists every year up to 20 years.

Why not just multiply by 7?

Because the chart does not age cats at an even pace. A cat reaches 15 in human years during its first year and 24 by the end of its second, and from then on it adds 4 a year. Multiplying by 7 would give 7 at 1 year and 70 at 10 years, where the chart gives 15 and 56.

Do neutered cats live longer?

In the study, neutered cats that died after 9 months lived 1.07 years longer on average than entire cats, with sex and breed taken into account. Entire cats had 4.29 times the odds of dying before 3 years of age. For cats that are already a few years old, the difference is much smaller, as the table above shows.

Do indoor cats live longer?

The study did not record whether cats lived indoors or went outside, so we have no figures to give, and that is why the calculator does not ask about it. The authors point out that outdoor access brings a risk of accidents, fights and infection.

Does breed matter?

In the study, crossbred cats had a life expectancy at birth of 11.89 years and purebred cats 10.41 years. Burmese and Birman had the longest life expectancy of the single breeds, and Sphynx the shortest, though only 18 Sphynx cats were in the study. The calculator distinguishes only between mixed breed and purebred.