Cat Age Calculator
Enter your cat’s age to see it in human years on the standard veterinary chart, and find out which life stage your cat is in.
Cat Age Calculator
Example Enter your cat’s age above.
Your cat’s age in human years
About 32 human years
4 years old · 15 at one, 24 at two, then 4 a year
Working
- Age: 4 years.
- 24 at age 2, then 4 human years for each year after: 24 + (4 − 2) × 4 = 24 + 8 = 32 human years.
- The old “× 7” rule: 4 × 7 = 28 — shown only for comparison.
- Life stage: 4 completed years → Young adult (1–6 years); mature adult from age 7, in 3 years.
How to use the cat age calculator
Type your cat’s age in years and months. The calculator shows the human-equivalent age, the life stage from the 2021 AAHA/AAFP Feline Life Stage Guidelines, when the next stage starts, and the old “× 7” figure for comparison, with the working underneath. Until you type, the example shows a 4-year-old cat. Your inputs are kept in the page address, so you can bookmark or share the result.
How cat years convert to human years
Age 1: 15 human years
Age 2: 24 human years
Over 2: 24 + 4 × (cat age − 2) This is the chart used by veterinary organizations in the US, including the feline age chart from the AAFP–AAHA Feline Life Stage Guidelines that AAHA reproduces on its pet age poster. Cats pack a lot of development into the first two years: by their first birthday they are fully grown, much like a teenager, and by two they are young adults in their mid-twenties in human terms. From then on each cat year counts as about four human years. Between whole years the calculator interpolates in a straight line; under 1 year it runs from birth through 10 human years at 6 months, the six-month figure on the age chart. Published charts stop at 25; beyond that the calculator keeps adding 4 a year and says so.
| Cat age | Human age | Cat age | Human age |
|---|---|---|---|
| 1 | 15 | 14 | 72 |
| 2 | 24 | 15 | 76 |
| 3 | 28 | 16 | 80 |
| 4 | 32 | 17 | 84 |
| 5 | 36 | 18 | 88 |
| 6 | 40 | 19 | 92 |
| 7 | 44 | 20 | 96 |
| 8 | 48 | 21 | 100 |
| 9 | 52 | 22 | 104 |
| 10 | 56 | 23 | 108 |
| 11 | 60 | 24 | 112 |
| 12 | 64 | 25 | 116 |
| 13 | 68 |
Cat life stages
The 2021 AAHA/AAFP Feline Life Stage Guidelines group a cat’s life into four age-based stages, plus an end-of-life stage:
- Kitten: birth up to 1 year.
- Young adult: 1–6 years.
- Mature adult: 7–10 years.
- Senior: over 10 years (from the 11th birthday in this calculator, counting completed years).
- End of life: defined by health rather than age, so it can come at any stage.
The stages matter because care priorities change: kittens need vaccines, parasite control and socialization; young and mature adults need weight control and dental care; and seniors benefit from earlier screening for the diseases that become common with age. The AVMA’s owner guidance uses a simpler rule and calls cats senior from about 7, so you will see both figures quoted. Ask your veterinarian how often your cat should be checked at its age.
Worked examples
- A 4-year-old cat: 24 + 4 × (4 − 2) = 24 + 8 = 32 human years. That is a young adult, with the mature adult stage starting at 7 — in 3 years. The “× 7” rule would say 28.
- A cat aged 12 years 6 months: 24 + 4 × (12.5 − 2) = 24 + 42 = 66 human years, a senior. The “× 7” rule would say 87.5 — too high, because it assumes the fast early aging carries on for life.
Tips
- Unknown birthday? Use your vet’s estimate, or count from the adoption date with the date difference calculator and add the age the shelter gave.
- Kittens change fast. In the first year a few weeks make a real difference, so enter months for a kitten.
- Have a dog too? Dogs age differently by size — try the dog age calculator. For exact ages in days from a birth date, use the age calculator.
Frequently asked questions
How old is my cat in human years?
A 1-year-old cat is about 15 in human years and a 2-year-old about 24. After that, add about 4 human years for each cat year: a 5-year-old cat is about 36, a 10-year-old about 56 and a 15-year-old about 76.
Is one cat year equal to seven human years?
No. Cats grow up far faster than that — a one-year-old cat is fully grown, more like a mid-teenager than a seven-year-old child — and then age more slowly, at roughly four human years per year. The “× 7” rule underestimates young cats and overestimates old ones.
At what age is a cat a senior?
The 2021 AAHA/AAFP Feline Life Stage Guidelines call cats seniors once they are over 10 years old; ages 7 to 10 are “mature adult”. The AVMA’s pet owner advice is more conservative and says cats are generally considered senior at about 7. Either way, it is a good time to talk to your vet about checkups and screening.
How can I tell how old a rescue cat is?
A veterinarian can estimate age from the teeth, especially in kittens and young cats, and from signs such as the coat, eyes and muscle tone in older cats. The estimate gets less precise with age. Enter the vet’s estimate here.
Why does the calculator say “about”?
Human-equivalent ages are a comparison of life stages, not a biological measurement. Individual cats age at different rates depending on genetics, health, weight and care, so treat the number as a rough guide to where your cat is in its life.