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Cat Age Calculator: Cat Years to Human Years.
Convert cat years to human years and find your cat’s life stage.
A 1-year-old cat is 15 in human years and a 2-year-old cat is 24; each year after that adds about 4. Enter your cat’s age below, in years or with decimals such as 2.5, to see its age in human years and its life stage, from kitten to senior.
Updated
INTERACTIVE TOOL
01 / Enter values
Your result
A 5-year-old cat
Life stage: young adult (1 to 6 years)
The old “× 7” rule would say 35, which is too low for young dogs and cats.
An estimate from the veterinary age chart: breed, weight and health change how fast a pet ages.
QUICK ANSWER
A cat reaches the equivalent of 15 human years in its first year and 24 by its second birthday. After that, each cat year counts as about 4 human years: a 5-year-old cat is 36, a 10-year-old cat is 56 and a 15-year-old cat is 76. Unlike dogs, cats age at about the same rate whatever their breed or size.
QUICK REFERENCE
Cat years to human years chart
| Cat’s age | Human years |
|---|---|
| 6 months | 10 |
| 1 years | 15 |
| 2 years | 24 |
| 3 years | 28 |
| 4 years | 32 |
| 5 years | 36 |
| 6 years | 40 |
| 7 years | 44 |
| 8 years | 48 |
| 9 years | 52 |
| 10 years | 56 |
| 11 years | 60 |
| 12 years | 64 |
| 13 years | 68 |
| 14 years | 72 |
| 15 years | 76 |
| 16 years | 80 |
| 17 years | 84 |
| 18 years | 88 |
| 19 years | 92 |
| 20 years | 96 |
How to convert cat years to human years
Count 15 for the first year and 9 for the second, then add 4 for every year after that: human years = 24 + 4 × (cat’s age − 2). A 12-year-old cat is 24 + 4 × 10 = 64. A 6-month-old kitten is about 10, already as mature as a child entering their teens.
Cat life stages
These are the stages in the 2021 AAHA/AAFP Feline Life Stage Guidelines used by veterinarians in North America.
- Kitten: birth to 1 year.
- Young adult: 1 to 6 years.
- Mature adult: 7 to 10 years.
- Senior: over 10 years, when yearly or twice-yearly check-ups and blood tests are recommended.
How long do cats live?
Indoor cats commonly live 12 to 18 years, and many reach their 20s; the oldest on record lived to 38. Outdoor cats tend to live shorter lives because of traffic, disease and fights. For dogs, which age differently by size, use the dog age calculator.
In short
How to use the Cat Age Calculator
- Fill in “Cat’s age”, for example 0.5 years.
- Read the result. It updates as you type, so you can change any value and compare.
Quick reference
Worked examples
| Cat’s age | Result |
|---|---|
| 0.5 years | 10 human years |
| 2 years | 24 human years |
| 7 years | 44 human years |
| 12 years | 64 human years |
| 18 years | 88 human years |
Quick reference
| Cat’s age | Result |
|---|---|
| 1 years | 15 human years |
| 2 years | 24 human years |
| 3 years | 28 human years |
| 5 years | 36 human years |
| 8 years | 48 human years |
| 10 years | 56 human years |
| 13 years | 68 human years |
| 15 years | 76 human years |
| 20 years | 96 human years |
Accuracy
How we checked this
We compared 4 results from this calculator with values we worked out independently, using exact decimal arithmetic and the published definitions, on October 26, 2026. 4 of 4 matched to the precision shown.
| Input | Independent value | This page | Match |
|---|---|---|---|
| 1 years | 15 | 15 human years | Yes |
| 2 years | 24 | 24 human years | Yes |
| 10 years | 56 | 56 human years | Yes |
| 15 years | 76 | 76 human years | Yes |
From the source
Understanding a cat’s life stage and lifestyle greatly impacts healthcare strategies.
Sources
GOOD TO KNOW
Frequently asked questions
How old is a 10-year-old cat in human years?
56 human years.
How old is a 15-year-old cat in human years?
76 human years.
How old is a 1-year-old cat in human years?
15 human years.
At what age is a cat a senior?
Over 10 years, according to the AAHA/AAFP life stage guidelines.