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How to Tell Your Cat’s Age in Human Years (With Chart)

Written by: Christian Adams

Last Updated on February 18, 2024 by Catster Editorial Team

toyger kittens

How to Tell Your Cat’s Age in Human Years (With Chart)

Nearly 43 million American households 1 have at least one cat. It’s easy to see why they are so popular. Felines are more independent than dogs, making them less work, especially for working families. However, that doesn’t mean they don’t require attention.

Age is a critical factor in many of the health decisions you’ll make. Comparing your pet’s age to human years puts it into a better perspective. However, it’s not a simple formula. Instead, it’s a dynamic quality that changes throughout your cat’s face divider 2

Kitten to Human Years Age Chart

how old is your cat in human years?
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Age becomes relevant even before you bring your pet home. One of the first decisions you’ll make is when that happens. It can mean the difference between a cat that handles the transition well to one that is nervous with behavioral issues. The next milestone is the time that you spay or neuter your pet. That can differ with the varying development of cat breeds.

Another critical decision involves your pet’s diet. Kittens and adult cats don’t have the same nutritional needs. For example, a younger pet must get more protein, calcium, and other nutrients to support its development. Likewise, a senior pet has differing requirements, too. All animals—including people—slow down as they age. That means dietary changes.

Not a One-Size-Fits-All Formula

Often pet owners believe the adage that one year of their cat or dog’s life equals seven in them. Unfortunately, that’s too simplistic. A cat becomes sexually mature around 6 months, depending on the breed. By that formula, a kitten is 3.5 years, which shoots holes into that 7-year theory. Instead, you’ll find it’s quite variable.

For one thing, it’s essential to consider your cat’s age in months when it’s under 1 year old. Then, figures also vary, depending on the animal’s life stage. Diet and health can play a role, too. Bear in mind that a feline’s lifespan isn’t necessarily the same as humans, either.3 cat face divider

Cat Age Chart in Human Years

Life Stage Age of Cat Human Equivalent Age
Kitten 0-1 month 0-1 year
2 months 2 years
3 months 4 years
4 months 6 years
5 months 8 years
6 months 10 years


7 months 12 years
12 months 15 years
18 months 21 years
2 years 24 years
Adult 3 years 28 years
4 years 32 years
5 years 36 years
6 years 40 years
Mature 7 years 44 years
8 years 48 years
9 years 52 years
10 years 56 years
Senior 11 years 60 years
12 years 64 years
13 years 68 years
14 years 72 years
Super Senior 15 years 76 years
16 years 80 years
17 years 84 years
18 years 88 years
19 years 92 years
20 years 96 years
21 years 100 years
22 years 104 years
23 years 108 years
24 years 112 years
25 years 116 years


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Do Indoor and Outdoor Cats Age at the Same Rate?

Indoor and outdoor cats may age the same physically, but that only scratches the surface. The first factor is lifespan. You can expect a pet kept indoors to live up to 15 years or more. A cat that lives outside live up to 5 years—if it can dodge the dangers of cars, predators, and disease.

Diet also becomes a part of the aging issues, especially for cats that fend for themselves by hunting. That adds a host of potential risks, including poisoning, internal or external parasites, and conflicts with the conservation of vulnerable species. The fact remains that cats adapt well to indoor life without any problem.

American shorthair and Scottish fold cat sitting on wooden box
Image Credit: Cat Box, Shutterstock

Signs of Aging in Senior Cats

A cat enters the senior life stage at about 11 years old. A pet may develop chronic health conditions at this time, such as arthritis and dental disease. These two issues, in particular, can cause other complications that can affect a cat’s lifespan.

A feline typically starts to slow down as she ages. She may lose muscle mass that can make getting around more difficult. She may develop arthritis. These conditions mean that you should feed your cat less and switch to a senior diet to prevent obesity. That can directly impact her quality of life and longevity.

Dental disease can bring on another set of equally disconcerting problems. If it hurts your cat to eat, she may go off of her food. That can, in turn, cause weight loss and nutritional deficiencies. An inadequate diet also puts your pet at risk for parasites and disease.

Other signs of aging include:
  • Hearing loss
  • Cataracts and vision loss
  • Cancer
  • Diabetes
  • Kidney disease

The risk of these conditions increases with age. Therefore, regular veterinary care is imperative for your cat’s health.

cat paw divider

Which Cat Breeds Live Longest?

Interestingly, the research shows that mixed or crossbred cats are more long-lived than their purebred counterparts. A review of the oldest felines according to the Guinness Book of World Records supports these findings. You might wonder, why is that true?

Perhaps the critical factor is breeding. If cats are inbred, there is a greater risk that the offspring will inherit an unwanted trait, such as deafness. If both related parents have a gene that codes for a disease, the chances are higher that the kittens will get the bad copy from both of them. On the other hand, mixed-breed cats that aren’t related will likely have healthier young.

A cat that is 15 years old has lived a long life. The fact remains that some animals can even live into their 30s with proper care and diet.

3 cat divider

Conclusion: How Old Is My Cat

Understanding how your cat ages can go a long way to ensuring a good quality of life. It’ll help you choose an appropriate diet and provide the best care, no matter what her life stage. The essential thing to remember is that your pet isn’t a little human. She has her unique physiology that determines her lifespan. Knowing what to expect as your pet ages is vital for her health.

Featured image: Kutikova Ekaterina, Shuterstock

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