Cat years to human years

Converting cat years to human years isn’t entirely straightforward. Here we look at how to understand your cat’s age, the feline life stages, and a (rough) cat-to-human-years calculation chart.

As a cat owner, we’re going to guess that at some point you’ve wondered how a feline’s age compares to a human’s. It used to be said that one cat year equals seven human years, but that’s way too simplistic. The fact is cats age differently from their human servants.

Cats mature much faster in their early life, while the rate at which they age slows down as they reach adulthood. Rather than making a straight age-for-age conversion, it’s better to understand your cat’s life stage, anticipating their changing needs as you grow together.

Protect your cat at any age with peace-of-mind cat insurance.

Early years: rapid growth and development

Cats age the fastest during their first two years. By the end of their first year, your cat will be roughly equivalent to a 15-year-old human. By this age, they’ve reached sexual maturity, their adult teeth have grown in, and their playful kitten energy is starting to balance out.

By the time your cat turns two, they’re about the same age as a 24-year-old person. They’re mature and energetic, plus fully developed both physically and socially. And they don’t have to worry about a career or getting on the property ladder.

This accelerated start explains why kittens grow and learn so quickly. It’s during this time that proper nutrition and socialisation are most important. You should also keep on top of vet care, taking them for health checks and vaccinations.

Find out more about how to look after a kitten, and how to keep on top of their week-by-week development.

Adulthood: the prime years

After the age of two, the general rule is that each additional cat year is roughly equivalent to four human years. So:

A 5-year-old cat would be about 36 in human terms
A 10-year-old cat would be around 56

These middle years are considered a cat’s prime. They’re active, confident and usually settled into their routines.

But just like humans in midlife, adult cats may start to experience subtle changes in metabolism and energy. Maintaining a balanced diet, ensuring regular exercise and scheduling annual vet visits are still a priority during this stage.

Dental care is also super important, as tartar and gum disease can develop over time and impact overall health. Find out how to brush your cat’s teeth here.

Senior cats: the golden years

Cats are typically considered senior around the age of 10, equivalent to a human in their mid-50s to early 60s. By the time they reach 15, they’re roughly 76 in human years.

Senior cats often become less active and sleep more. They might also develop age-related conditions such as arthritis, reduced vision or kidney disease.

Despite this, many cats live well into their late teens or even early 20s, thanks to advances in veterinary medicine and improved understanding of feline care.

So while an 18-year-old cat is comparable to an 88-year-old person – and they may move more slowly accordingly – they can still enjoy a high quality of life with the right care and attention.

Find out more about the special needs of older cats.

How old is your cat? Cat years to human years conversion table

Cat's age:	Corresponding human age:
1	15
2	24
3	28
4	32
5	36
6	40
7	44
8	48
9	52
10	56
11	60
12	64
13	68
14	72
15	76
16	80
17	84
18	88
19	92
20	96
21	100

More useful information, guides and advice on looking after your old cat:

Written by: Owe Carter
Last reviewed on: 19 November 2025

About the Author

Owe Carter is a writer specialising in insurance and pets. After a 10-year shift as lead copywriter at Confused.com, he's written for numerous consumer, motor and personal-finance businesses - including Go.Compare, Admiral, AA Driving School, Ageas, Principality, MoneyWeek and Look After My Bills. He has two cats, Niblet and Slinky, and a cavalier named Momo.