Cat Years to Human Years Calculator

Quick answer

A one-year-old cat is roughly equivalent to a 15-year-old human, while a two-year-old cat is roughly equivalent to a 24-year-old human. These are guides to how cats mature, not exact age conversions. After that, every cat year adds about 4 human years. That makes a 10-year-old cat about 56 in human years and a 15-year-old cat about 76.

Cat years to human years chart

Find your cat's age on the left to see their age in human years. The figures reflect the conversion in the Feline Life Stage Guidelines from the American Association of Feline Practitioners and American Animal Hospital Association, which are used by vets across Australia.

How to work out cat years

The maths isn't too difficult once you know the pattern.

1. A cat's first year is worth 15 human years.
2. Their second year is another 9, so a 2-year-old cat is about 24.
3. Every year after that adds about 4 human years.

So a 10-year-old cat is 24 + (8 x 4) = 56.

Cats age at much the same rate whatever their breed or size, so one chart works for nearly every cat, from a Burmese or a Ragdoll to the everyday domestic shorthair most of us know as a moggie.

Is one cat year really seven human years?

The seven-year rule is wrong at both ends. It makes a 1-year-old cat the same as a 7-year-old child, when most cats are fully grown and able to have kittens by then, which puts them closer to 15. At the other end it makes a 15-year-old cat 105, when they're really about 76.

Cat life stages and what they need

Kitten (birth to 1 year)

Rapid growth, lots of play and plenty to learn. This is the time for your kitten's F3 vaccination course, a microchip and council registration, and desexing, which is compulsory for cats in some states and territories. A good kitten food and early handling help them grow into a confident adult.

Young adult (1 to 6 years)

Your cat is at their physical peak. Keep up a yearly check-up with vaccine boosters, flea and worm prevention, and dental care.

Mature adult (7 to 10 years)

Roughly the same as a person in their mid 40s to mid 50s. Weight gain, dental disease and early kidney changes often start appearing here, so the annual check-up matters more than ever.

Senior (10 years and over)

Most vets suggest a check-up every six months from here, with regular blood tests to pick up kidney disease, an overactive thyroid and diabetes early. These are common in older cats and much easier to manage when caught early. Older cats also feel the heat, so make sure they have a cool, shady spot and plenty of fresh water through an Aussie summer.

End of life

As your cat nears the end of their life, the focus shifts to comfort, pain relief and quality of life. Our free quality of life assessment can help you think it through, and our vets are always happy to talk it over with you.

How long do cats live in Australia?

Most indoor cats live 12 to 18 years, and plenty reach their 20s. Cats that roam tend to have shorter lives because of cars, fights, snake bites and disease. That's one reason more councils, particularly in Victoria and the ACT, now require cats to stay on their owner's property at night or around the clock. Check your local council's rules, and if your cat is used to going out, a secure cat run or enclosure is a great middle ground.

Signs your cat is getting older

• Sleeping more and playing less.
• Grooming less, with a scruffy or matted coat.
• Losing weight, even when they're eating well.
• Drinking and weeing more.
• Stiffness, or no longer jumping onto favourite spots.
• Going to the toilet outside the litter tray.
• Yowling at night or seeming confused.
• Bad breath or dropping food.

Cats are experts at hiding pain, so small changes can mean more than they seem. If you notice any of these, book a check-up rather than waiting for the next one.

Senior cat check-ups at home

Australia has around 5.8 million pet cats, but only about three in four saw a vet last year, compared with nearly nine in ten dogs. For many owners the carrier, the car and the waiting room are the hard part, and older cats find it all the harder. A Pawssum vet can come to you for a senior check-up and blood tests, so your cat is calm in the comforts of their own home. We're open 7 days a week from 6:00am to 11:00pm, including public holidays, and have cared for more than 380,000 pets across Australia with a 4.6-star rating from more than 2,805 Google reviews.

How we determined these figures

Our calculator and chart use the cat age conversion and life stages from the Feline Life Stage Guidelines by the American Association of Feline Practitioners and American Animal Hospital Association. Australian pet and vet visit figures come from the 2025 Pets in Australia survey by Animal Medicines Australia. Every figure on this page has been reviewed by a Pawssum partner vet.

The calculator gives you an estimate. Every cat ages a little differently, and your vet is the best person to advise you about your cat.

Cat age FAQs

Is 1 year 7 years for a cat?

No. A 1-year-old cat is about 15 in human years. Cats grow up much faster than the seven-year rule suggests.

At what age is a cat considered old?

Cats are considered seniors from about 10 years old, which is roughly 56 in human years.

How old is a 7-year-old cat in human years?

About 44.

How old is a 15-year-old cat in human years?

About 76.

How old is a 6-month-old kitten in human years?

About 10. By their first birthday they'll be around 15.

How often should a senior cat see the vet?

Most vets recommend a check-up every six months for cats aged 10 and over, with blood tests at least once a year.

Do indoor cats age differently from outdoor cats?

They age at the same rate, but indoor cats usually live longer as they avoid traffic, fights and many infectious diseases.

How can I tell how old my cat is if I don't know their birthday?

A vet can estimate your cat's age from their teeth, eyes, coat and muscle tone. Teeth are the most reliable guide in young cats. In older cats, cloudy eyes and a thinner, coarser coat give useful clues.

References

• Quimby J et al. 2021 AAHA/AAFP Feline Life Stage Guidelines. Journal of Feline Medicine and Surgery
• Animal Medicines Australia (2025). Pets in Australia: A national survey of pets and people
• Australian Veterinary Association (2025). Australians' love for pets grows, but cost pressures bite

Share your home with a dog too? Try our dog age calculator. Want to check your cat is eating the right amount for their age? Use the pet calorie calculator.