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Cat age calculator: cat years to human years

Convert your cat’s age into human years and see their life stage, with a chart from 1 to 22 years.

Estimated life stage

Rough human-age comparison
36 years
Life stage
Prime adult

This is only a broad estimate. Breed, body size, lifestyle and health history can all affect how your pet ages.

If your cat is slowing down, losing weight, eating differently or behaving differently, book a check-up rather than assuming it is simply getting older.

Cat years to human years chart

Find your cat’s age in the left-hand column to see the rough equivalent in human years.

Cat’s age Human years Life stage
1 year 15 Junior
2 years 24 Junior
3 years 28 Prime adult
4 years 32 Prime adult
5 years 36 Prime adult
6 years 40 Prime adult
7 years 44 Mature adult
8 years 48 Mature adult
9 years 52 Mature adult
10 years 56 Mature adult
11 years 60 Senior
12 years 64 Senior
13 years 68 Senior
14 years 72 Senior
15 years 76 Super senior
16 years 80 Super senior
17 years 84 Super senior
18 years 88 Super senior
19 years 92 Super senior
20 years 96 Super senior
21 years 100 Super senior
22 years 104 Super senior

How to use it

How the pet age calculator works

Enter your pet’s age and, for a dog, their size. Dogs and cats grow up quickly: their first year is roughly 15 human years and their second about 9 more. After that a cat adds about 4 human years a year, and a dog between 4 and 7 depending on size, because larger breeds age faster. Rabbits and horses use simpler estimates.

Treat the result as a prompt to think about your pet’s care, not as a diagnosis. Two animals born on the same day can age very differently. What matters most is whether you have noticed changes in their weight, movement, appetite, thirst, toilet habits or behaviour.

What the result means

  • For a young animal, ask your vet about growth, vaccinations, parasite prevention, socialisation and neutering.
  • For an adult animal, keep an eye on weight and dental health, stay up to date with parasite prevention, and learn what is normal for them.
  • For a mature or senior animal, watch for changes in weight, movement, teeth, thirst, appetite, toilet habits or behaviour, and consider check-ups every six months.
  • For a horse, age is only part of the picture. Workload, teeth, hoof care, body condition and signs of stiffness also matter.

Changes to discuss with your vet

Contact your vet if your pet slows down suddenly, gains or loses weight without an obvious reason, drinks more, seems stiff, eats differently, develops bad breath, coughs, hides, becomes unsettled or stops enjoying their usual activities. Don’t assume a change is simply part of getting older.

Common questions

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

Roughly 15 in human years. Health, lifestyle and breed all make a difference, so treat it as a guide.

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

Roughly 24 in human years. Health, lifestyle and breed all make a difference, so treat it as a guide.

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

Roughly 56 in human years. Health, lifestyle and breed all make a difference, so treat it as a guide.

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

Roughly 80 in human years. Health, lifestyle and breed all make a difference, so treat it as a guide.

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

Roughly 96 in human years. Health, lifestyle and breed all make a difference, so treat it as a guide.

At what age is a cat a senior?

International Cat Care calls cats seniors from 11 to 14 and super seniors from 15. Cats of 7 to 10 are mature adults.

Is one pet year the same as seven human years?

No. It is a popular shortcut, but animals don’t age at a fixed rate. Dogs and cats mature quickly in their first two years, then age more slowly, and large dogs age faster than small ones.

Why does dog size change the result?

Larger dogs tend to have shorter lifespans and often reach their senior years earlier than smaller dogs. The calculator uses size to reflect that broad difference.

Does the calculator diagnose health problems?

No. It gives a rough life-stage estimate. It can’t explain symptoms or replace a veterinary examination.

Use the result as a starting point

These tools are planning aids, not a diagnosis or a replacement for veterinary advice. If a pet is unwell, has eaten something risky, or you are unsure what to do next, contact a vet.

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