Cat years to human years: age chart

A cat's first year is worth about 15 human years, the second year about 10, and every year after that about 4. So a 2-year-old cat is roughly 25 in human years, a 10-year-old cat is about 57, and a 15-year-old cat is about 77.

The chart below covers every age from 1 to 25. To check a specific breed, use the pet age calculator, which also tells you the life stage for that breed.

How old is my cat in human years? The chart

The life stages shown are the ones this site uses for domestic shorthair, domestic longhair and mixed-breed cats. Some pedigree breeds reach each stage a year or two sooner or later.

These numbers are estimates of life stage, not a health assessment. A lean, active 14-year-old and a 14-year-old with kidney disease are the same age on the chart and in very different places.

How to calculate cat years

1. Count 15 human years for the first year.
2. Add 10 for the second year, which makes 25 at age two.
3. Add 4 for every year after that.

For a 12-year-old cat that is 15 + 10 + (10 x 4) = 65. Unlike dogs, cats do not need a different number for different sizes. If you have a dog too, the dog years to human years chart shows how much size changes the answer there.

Why the first two years count for so much

Cats do most of their growing up early. By its first birthday a cat is close to full size and able to have kittens, which is why that year counts as 15. By two it is a settled adult of about 25. After that, aging is steadier, at about 4 human years for each calendar year. This is also why the old idea of multiplying by seven does not work for cats: it makes young cats too young and old cats too old.

Common ages, answered

• How old is 7 in cat years? A 7-year-old cat is about 45 in human years. This is the start of the mature adult stage.
• 12 year old cat in human years: about 65. A senior, and for a few breeds already geriatric.
• How old is a 13 year old cat? About 69 in human years.
• 16 year old cat in human years: about 81.
• 17 year old cat in human years: about 85.
• 18 year old cat in human years: about 89.
• 20 year old cat: about 97 in human years. Uncommon, but well within what a well-cared-for indoor cat can reach.

If you are wondering how many years a cat can expect at these ages, how long cats live has typical lifespans by breed.

How to tell how old a cat is

If your cat was a stray or came from a shelter without records, nobody knows the exact age. A few physical clues narrow it down. They are rough, and they overlap a lot between cats, so treat your own guess as a starting point and ask your vet to refine it at the next exam.

Teeth

Teeth are the most useful clue in a young cat. Kittens have small, sharp baby teeth, and the adult teeth are usually all in by around six to seven months. After that, vets look at wear and tartar. Clean white teeth suggest a young adult. Yellowing, tartar, worn tips, gum disease and missing teeth suggest an older cat, although diet, genetics and dental care change the picture a great deal.

Eyes

A young cat's eyes are clear and bright, with a smooth, evenly colored iris. In older cats the lens often develops a faint bluish haze and the iris can look thinner or slightly ragged at the edge. Cloudiness can also be a sign of eye disease, so new changes are worth showing to a vet.

Coat

Young cats have a soft, fine coat and keep it immaculate. With age the coat tends to get coarser, and some cats grow scattered white or gray hairs. Old cats often groom less, so you may see greasiness, dandruff or mats along the back and hips.

Muscle tone

Younger cats are firm and muscular across the shoulders and back. Older cats commonly lose muscle, so the spine, hips and shoulder blades feel more prominent and the skin hangs a little looser. Thick, brittle or overgrown claws are another sign of an older cat.

None of these is precise. A vet looking at all of them together can usually place a cat in a broad age range, and that is enough to pick the right care. If you are considering an older shelter cat, adopting a senior cat covers what to expect.

What each life stage means for care

• Adult, up to about 6 (human 15 to 41). The prime of life. A yearly checkup, a steady routine and a healthy weight.
• Mature adult, 7 to 9 (human 45 to 53). The cat looks the same, but this is when weight gain and dental disease tend to set in. A good time to ask your vet about baseline bloodwork, so later changes are easy to spot.
• Senior, 10 to 14 (human 57 to 73). Vet visits twice a year are commonly recommended, usually with blood and urine tests. Kidney disease, an overactive thyroid and arthritis become more common. See when a cat is considered a senior for what should change.
• Geriatric, 15 and over (human 77 and up). More frequent checks, comfort at home and close attention to weight, appetite and litter box habits.

Whatever the stage, a sudden change is a reason to call your vet and not something to put down to age. That includes a cat that stops eating, loses weight, drinks much more than usual or hides.

Check your own cat

Breed moves the stages a little. On this site cats become seniors at 9, 10 or 11 depending on breed, and geriatric anywhere from 12 to 16. The cat age calculator gives the human-years figure and the life stage for your cat's breed, and the senior cat guide covers the health checks, food and home changes that matter from there.

This chart is general educational information, not veterinary advice. Human-year equivalents and life stages are estimates based on averages, and the physical signs of age described here are rough clues only. Your veterinarian is the right person to estimate your cat's age and assess its health.