Cat Years to Human Years Calculator

“How do I convert cat years to human years?” It’s a question every cat owner has asked themselves at one point or another.

You’ve probably heard that human to cat years convert at roughly seven to one, so it might be surprising to learn that that’s not strictly true. So, what's the best way to work out your cat's age in human years? Whether you're a pet parent looking for a cat sitter and you want to list their human years, or you're simply a cat fanatic interested in the topic (we get it), our handy cat age calculator will help you crunch the kibble (sorry, numbers)…

How do you convert cat years to human years? Cat to human years chart

Working out cat to human years isn't as simple as saying "one human year equals seven cat years". Although there's no real scientific way to figure out what cat years are in human years, some research makes it easier to calculate. The American Animal Hospital Association (AAHA) recommends using the following metrics to determine your cat's human age:

• First year of a cat’s life = 15 human years
• Second year of a cat’s life = nine human years
• Every subsequent year =  four human years

These AAHA guidelines are based on both the physical and behavioural stages of a cat’s life, matched to similar stages of a human's life. If you convert a cat to human years, your adorable, goofy kitten is actually a teenager. And, by the time they're two years old, they're already hitting their mid-twenties. 

In a similar vein, a senior cat of around 15 years of age could actually be the equivalent of 76 human years! 

Trying to do the maths? Put the calculator down. Our handy ‘cat to human years chart’ below makes it easy to see how old your precious puss is.

How do cats age?

Cats generally age quite quickly at the beginning of their life. For example, it takes just four weeks for kittens to go from helpless newborns to inquisitive fluffballs who are steady on their feet and ready to play with their littermates. 

The older they get, the slower the ageing process becomes. Most cats are fully developed by the time they turn three. Once they reach this age, it's hard to tell how old your cat is as their outward appearance doesn't change much. 

Of course, our human years to cat years calculator is just a guideline. There might be some variances based on your cat's breed, lifestyle and environment. That said, it's easier to convert cat years to human years than it is for dogs. Pooches have much greater variations depending on size and breed. 

Thanks to better nutrition and vet care, cats are living longer than ever. This has led to the various life stages of a cat being refined in recent years. According to International Cat Care, cats are now considered to be “elderly” or “senior” once they reach 11 years old, with “senior” cats sitting in the 11-14 age bracket. Think of them as 60-72 year old humans, who still have plenty of independence but might need to take things a little slower. 

And if you’ve got a 15+ year old cat in your household, then congrats! You’ve got yourself a loving and loyal "geriatric" cat. If they were humans they'd be 76 and older, and have definitely earned the right to snooze for a few extra hours in their favourite sun-soaked spot.

How can I tell how old my cat is?

Unless you've had your kitty since the day they were born, it's hard to tell how old your cat is, and converting cat years to human years isn't nearly as simple. After all, you can't simply ask them their birthday. It's important to have a rough idea of your cat's age as it helps you understand how to care for them. Younger cats have different needs to their geriatric counterparts, so knowing how old they are will stand you in good stead for giving them the best life possible. 

Your vet will be able to conduct a full-body examination to work out how old your furry friend is. You can also look for the following signs and make a guesstimate:

Teeth: dental problems can be hereditary, but can also be a sign of age. Kittens get their first milk teeth at around 2 to 4 weeks, and permanent teeth by the time they are 3 to 4 months. Yellowing teeth can be a sign of ageing and this could begin as early as one year old. Missing teeth may suggest your cat is getting on in years – and is likely to be aged 10 or older. 

Coat: kittens have soft, fuzzy fur, but as they age it becomes thicker and coarser. As cats reach seniority you might notice patches of lighter coloured hair – similar to how humans go grey. Grooming is another telltale sign, as senior cats may not groom themselves as much or as regularly as they did in their younger years.

Eyes: they say eyes are the windows to the soul, but in this case, they can also be a great indicator of your cat’s age! While healthy young cats and kittens have bright and clear eyes, by the time a cat reaches 10 years of age their eyes may start to become cloudy and/or teary. 

Cat years to human years - A quick reference guide

How old is a 1 year old cat in human years?

A one year old cat is the equivalent to 15 human years old.

How old is a 2 year old cat in human years?

A two year old cat is the equivalent to 24 human years old.

How old is a 3 year old cat in human years?

A three year old cat is the equivalent to 28 human years old.

How old is a 4 year old cat in human years?

A four year old cat is the equivalent to 32 human years old.

How old is a 5 year old cat in human years?

A five year old cat is the equivalent to 36 human years old.

How old is a 6 year old cat in human years?

A six year old cat is the equivalent to 40 human years old.

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

A seven year old cat is the equivalent to 44 human years old.

How old is an 8 year old cat in human years?

An eight year old cat is the equivalent to 48 human years old.

How old is a 9 year old cat in human years?

A nine year old cat is the equivalent to 52 human years old.

How old is a 10 year old cat in human years?

A 10 year old cat is the equivalent to 56 human years old.

How old is an 11 year old cat in human years?

An 11 year old cat is the equivalent to 60 human years old.

How old is a 12 year old cat in human years?

A 12 year old cat is the equivalent to 64 human years old.

How old is a 13 year old cat in human years?

A 13 year old cat is the equivalent to 68 human years old.

How old is a 14 year old cat in human years?

A 14 year old cat is the equivalent to 72 human years old.

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

A 15 year old cat is the equivalent to 76 human years old.

How old is a 16 year old cat in human years?

A 16 year old cat is the equivalent to 80 human years old.

How old is a 17 year old cat in human years?

A 17 year old cat is the equivalent to 84 human years old.

How old is an 18 year old cat in human years?

An 18 year old cat is the equivalent to 88 human years old.

How old is a 19 year old cat in human years?

A 19 year old cat is the equivalent to 92 human years old.

How old is a 20 year old cat in human years?

A 20 year old cat is the equivalent to 96 human years old.

Do all cats age the same?

Just like humans, not all cats age alike. After all, some people are still the picture of health in their late seventies, while others show the signs of a life well-lived. It's the same for cats. Our feline friends typically live 10-15 years on average (which in cat to human years is between 56 and 76 years old), but they can live up until they're 21 and older – 100 in human years! In these cases when you're working out human to cat years, your 100 year old might be a lot more sprightly than a typical centenarian.

Often your furry friend's lifestyle will have an impact on how fit and healthy they are as they grow older. Similar to humans, diet and exercise are important. Keeping your cat physically fit through playing, or letting them climb trees, can help them to age gracefully. 

Feeding them a healthy diet – and keeping tidbits to a minimum – will help to keep them in tip-top shape. Choose a complete cat food tailored towards their age. Junior and senior cats have different nutritional needs, so it's important to meet these.

Indoor cats tend to live longer than those who are allowed to roam outdoors, although letting your cat explore gives them a more natural environment (and may help to reduce the symptoms of any cat allergies by airing out dander). If you have an outdoor cat, you can increase their chances of reaching a ripe old age by keeping them inside at night. Neutering your pet also reduces the chance of them wandering too far from home. It also cuts down the chances of them falling ill from diseases caught during mating or fighting with romantic rivals.

Caring for your cat at every stage

As cats age, their needs, personality and temperament may change. From playful kittenhood to grouchy senior status, it's important to know how to care for your cat at every stage of their life. This will ensure your kitty is getting the love, care and attention they deserve (and often, demand).

As well as buying specialist food for each stage of life, you should also think about the following:

Kitten (0-six months): in cat to human years, this is like having a child under seven in your home. And just like a human child, they've got lots of energy and curiosity. They're likely to get into mischief if you leave them unsupervised. Keep a close eye on them, be patient and show plenty of love.

Junior (six months-two years): this is your cat's adolescence in human terms, so it's natural to feel like you're living with a hormonal teen. And, just like with teenagers, now’s the time to introduce certain rules and boundaries. 

Prime (three to six years): according to our cat to human years calculator, your feline friend is now like a 20- or 30-something human. They understand boundaries – although might still act out from time to time – and are happy doing their own thing.

Mature (seven to ten years): as your cat reaches middle age in human years, you might need to pay a little more attention to their health. At this age they become more prone to conditions like obesity, high blood pressure and cancer. 

Senior/geriatric (11+): in cat to human years, you're now living with a pensioner. The main thing is keeping them comfortable and healthy. Make sure food, water and cat litter are easy to access, and get ready for plenty of lazy cuddles.

Whatever your cat's age, in human years or otherwise, we can all agree that they're members of the family. Working out cat years to human years just makes it easier to put their different needs into context.

When you're away on holiday or travelling for work, you can make sure your cat gets the care and attention they need by hiring a TrustedHousesitter. Knowing your feline friend is getting the kind of attention they're used to from an experienced cat lover makes it much easier to relax and enjoy yourself.