How to tell how old a cat is: teeth, eyes, coat and more

You can estimate a cat's age from its teeth, eyes, coat, muscle and behavior, but only as a range. A kitten can be aged to within a few weeks by its teeth. An adult cat can usually only be placed in a band: young adult, mature adult, senior or geriatric. A vet's estimate is the best one you will get, and it is still an estimate.

No single clue is reliable alone. Each is changed by diet, illness and the life the cat has led, so look at all of them together.

How do you tell how old a cat is? The clues at a glance

The age bands are the ones this site uses. They are explained in when a cat is considered a senior.

Teeth: precise in kittens, rough in adults

Teeth come through on a fairly fixed schedule, which is why kittens are the easy case.

• About 2 to 4 weeks: the tiny front baby teeth appear.
• About 3 to 6 weeks: baby canines, then the baby teeth along the cheeks.
• About 6 to 8 weeks: a full set of baby teeth.
• About 3 to 4 months: adult front teeth start to replace them.
• About 6 to 7 months: all the adult teeth are in.

Other kitten clues back this up. Eyes open at roughly one to two weeks. They are blue at first, and the adult color comes in from about six or seven weeks.

Once the adult teeth are in, the mouth only shows wear and tear. Clean white teeth suggest a cat of a year or two. Yellowing and tartar on the back teeth are common by early adulthood. Heavy tartar, receding or inflamed gums and worn, broken or missing teeth are more typical of an older cat.

This is where estimates go wrong. Dental disease varies widely between cats. A 4-year-old can have a bad mouth, and a 12-year-old that has had its teeth cleaned can have a tidy one. Treat teeth as one clue, and see dental care for older pets if the mouth looks sore.

Eyes: lens haze and iris changes

A young cat's lens is clear. As cats age the lens hardens and takes on a faint bluish-gray haze, most easily seen when light catches the eye from the side. It is a normal aging change and usually shows from somewhere between about 7 and 10 years on. On its own it usually has little effect on sight.

The colored part of the eye changes too. In old cats the iris can thin, so the edge of the pupil looks ragged or moth-eaten and the pupil may not close down fully in bright light. That is most often seen in cats of 10 and over.

Do not assume every change is age. A white or solid-looking lens can be a cataract, and brown spots on the iris need a vet to look at them because a few turn out to be tumors. See why an old cat's eyes look cloudy.

Coat, claws and skin

Young cats have fine, soft fur that gets thicker and coarser through adulthood. Seniors may show scattered white hairs, though cats gray far less than dogs.

The more useful sign is grooming. An older cat with stiff joints cannot reach its back and hips, so the coat there turns greasy, flaky or matted. The claws tell the same story: older cats scratch less, so the nails grow thick and brittle and may not fully retract. An unkempt coat can also mean illness or pain at any age, so read why an old cat stops grooming before putting it down to age.

Muscle and body shape

Run a hand along the spine and over the hips and shoulder blades. A young adult feels firm and well covered. Many middle-aged cats are at their heaviest, with a pad of fat on the belly. From the senior years cats tend to lose muscle, so the backbone, hip bones and shoulder blades stand out even when the belly still sags.

Muscle loss is a clue to age, but it is also a sign of kidney disease, an overactive thyroid, diabetes and other illness. A bony cat needs a vet visit, not just an older age on its record.

Can you tell how old a cat is by their whiskers?

No. Whiskers do not tell age. Their length goes with the size and breed of the cat, and they are shed and regrown throughout life. A few cats get a white whisker or two as they age, and some have mixed colors from kittenhood, so color is no guide either.

Can a vet tell how old a cat is?

A vet can give a good estimate, and it is the one to use. For a kitten it is often accurate to within a few weeks. For an adult the honest answer is a range of a few years, such as "probably 8 to 11".

The vet looks at the same things described here, with a trained eye and more tools: a full look at the mouth, an eye exam with a light, a body and muscle score, and how the joints feel. Blood and urine tests, blood pressure and sometimes X-rays add evidence. X-rays can show whether a young cat is still growing, and arthritis in the spine and joints suggests an older one. None of these gives a birth date.

Young cat vs old cat: how to tell if your cat is old

The hard call is between a mature adult of 7 to 9 and a true senior. These point toward senior:

• A bluish haze in both lenses, or a ragged edge to the iris.
• Backbone and hips that feel sharper than they look.
• Pausing before a jump, taking stairs one at a time, or using a chair to reach the counter.
• A coat that is unkempt over the lower back.
• Thick claws that click on hard floors.
• More sleep, less play, and louder meowing at night. Tell the vet about night crying, because it can also be a sign of illness.

A mature adult usually has some tartar and a calmer manner, but clear eyes, good muscle, a tidy coat and easy jumps.

How old is my cat? A quick checklist

1. Does it have baby teeth, a mix, or all adult teeth?
2. Are the teeth white, yellowed with tartar, or worn and missing?
3. Is the lens clear, or is there a blue-gray haze?
4. Is the coat sleek, or clumped over the back?
5. Is the back well muscled, or can you feel the spine and hips easily?
6. Does it jump to a counter in one go, or hesitate?

Mostly first answers suggest a young adult, a mix suggests a mature cat, and mostly last answers suggest a senior. It is a rough guide, not a result.

How to find out how old your cat is

Before estimating, check whether a record exists.

• Microchip. Any vet or shelter can scan for one. The registry may hold a birth date and a previous owner.
• Adoption paperwork. Shelters record an estimated age at intake. Ask how it was arrived at.
• Previous vet records. If the cat was first vaccinated as a kitten, that date gives the age to within a few weeks.

If there is nothing, ask your vet for an estimate and have it written in the record. Then use it: the pet age calculator and the cat years to human years chart turn it into a human age and a life stage. If you are taking in an older cat, adopting a senior cat covers the first vet visit.

The exact number matters less than the stage. A cat that looks 10 or more should have senior checkups and screening whether it is really 9 or 13. Many indoor cats live well into their teens, so a late estimate is not bad news. See how long cats live.

Call the vet promptly if

Several signs that look like old age are signs of illness that can often be treated. Book a visit soon if a cat of unknown age:

• Is thin or losing weight, with or without a big appetite.
• Drinks or urinates more than you would expect.
• Has a red, sore or foul-smelling mouth, drools, or drops food.
• Has a cloudy, red, squinting or bulging eye, or pupils of different sizes.
• Has a matted coat, limps, or resists being touched.

Go to a vet or emergency clinic now if the cat is breathing with effort, is straining and cannot pass urine, or has suddenly lost its sight. Go the same day if it has stopped eating.

This article is general educational information, not veterinary advice. The signs described are rough guides, and dental disease, illness and a hard life can make a cat look older or younger than it is. Only an examination can give a reasonable estimate of your cat's age, and decisions about its tests, diet and care should be made with your own veterinarian.