How to Tell the Age of a Cat (Even a Stray): Teeth, Eyes, Coat and Body Clues

Start with the teeth: all permanent teeth are in by about 6 months, yellowing and tartar build up from 1–2 years, and wear or missing teeth point to an older cat. Then check the eyes (cloudy lenses), coat and muscle to narrow the range. A vet can usually estimate within a few years.

If you're trying to work out how to tell the age of a cat that came without paperwork, you're not alone. Rescues, strays and "the cat that moved in" are all mysteries. The good news is that a few clues, taken together, get you a useful range. Once you have a guess, our cat age calculator turns it into human years.

How to tell a cat's age: the quick checklist

No single clue is perfect. Use all of these, then think in ranges:

1. Teeth: color, tartar, wear, missing teeth.
2. Eyes: clarity, and for kittens, color.
3. Coat: softness, thickness, grooming.
4. Body: muscle tone, weight, posture.
5. Behavior: energy level, playfulness, stiffness.

A healthy 4-year-old and a stressed, underfed 8-year-old can look alike. That's why a vet exam beats guessing.

Teeth: the most reliable clue

Teeth are the best tool you have, especially in the first year. Here's the general pattern:

Diet, genetics and dental care change all of this. A cat with a lifetime of dental cleanings can look younger than it is, and a cat with dental disease can look older.

Want a closer look at the teeth alone? See our cat teeth age chart.

A safety note: don't pry open a stray's mouth. Frightened cats bite. A gentle lip lift on a calm cat is fine, and a vet can do a proper exam.

Eyes, coat and muscle tone

Eyes. Kittens are born with blue eyes, which change to their adult color over the first few months. Clear, bright eyes suggest a young or healthy adult. A cloudy or bluish haze in the lens is common in older cats and is often harmless, but it can also be cataracts or other eye disease, so let a vet check.

Coat. Kittens have soft, fluffy fur. Young adults have dense, glossy coats. Older cats often have a coarser, thinner or greasy coat, since arthritis and dental pain can make grooming hard. Some cats gray a bit around the muzzle.

Muscle and weight. Young cats are lean and springy. Middle-aged cats often carry a little more weight. Very old cats can look bony along the spine and hips, with visible muscle loss.

Movement. Stiffness, hesitating before a jump, or sleeping most of the day can point to age, or to arthritis at any age.

Estimating a stray or rescue cat's age

If a stray shows up at your door:

1. Check for a microchip. A vet or shelter can scan for free or cheaply. It might lead to records.
2. Ask around. Neighbors, lost-cat groups and local shelters sometimes know.
3. Look at teeth, eyes and body, as above.
4. Book a vet visit. They'll also check for illness, parasites and spay/neuter status.

How can you tell if a stray kitten is under 8 weeks? A few signs:

• Weight. Kittens gain about a pound a month for the first four months, so a kitten under about 2 lb (0.9 kg) is likely under 8 weeks.
• Teeth. Only tiny baby teeth, with no permanent teeth.
• Eyes. Still blue, and very young kittens (under about 2 weeks) may not have opened them.
• Behavior. Wobbly walking, still nursing or needing bottle feeding.

Kittens this young need warmth, special feeding and a vet or rescue's help. Don't feed cow's milk.

Kitten vs adult vs senior: age-range table

The stages follow the AAHA/AAFP Feline Life Stage Guidelines. For what changes in later years, see what age a cat is considered senior.

How a vet estimates age, and why it's still a range

A vet looks at teeth, eyes, coat, muscle and joints, and may run bloodwork if the cat seems old. But even experienced vets say things like "probably 4 to 6 years." Cats age at different speeds, and health, diet and genetics muddy the picture.

Expect a range, and remember that it's fine to pick a "birthday" for your cat. Many rescues use a shelter-assigned date so you can track vaccines and checkups.

Convert the estimate to human years

Let's say your vet says your rescue is about 6 to 10 years old. A common rule: 1 year = 15 human years, 2 = 24, then +4 for each year after that.

1. At 6 years: 24 + (4 × 4) = 40 human years.
2. At 10 years: 24 + (8 × 4) = 56 human years.
3. Middle of the range, 8 years: 24 + (6 × 4) = 48 human years.

So your cat is roughly "40 to 56" in human terms. Plug in your own estimate with the cat age calculator, or compare pets with the pet age calculator. A healthy weight matters at any age, so try the cat BMI calculator too. And if you have a kitten, you may want to know when it will stop growing.

When to call your vet

Any newly adopted stray or rescue needs a checkup. Call sooner if you see:

• Sneezing, discharge from the eyes or nose, or crusty eyes.
• Diarrhea, vomiting or not eating for more than 24 hours.
• Weight loss, a bony body or a swollen belly.
• Difficulty breathing.
• Fleas, ear mites or bald patches.
• Limping, or an inability to jump.
• Straining in the litter box, especially a male cat. That's an emergency.
• Weakness, cold body or unresponsiveness in a kitten.