Cat Age Chart
Cat years 1 to 20, with life stage.
Starting estimate from a published table. Your vet knows your pet.
How to use the cat age chart
- Find the cat's whole year in the grid, or type it in the box. The page opens on year 15.
- Read human years in the middle column and the stage on the right.
- Remember that year 1 is already past kitten, and year 10 is still mature adult.
- For an age with months, leave this grid. A half year is not a row.
How to read this chart
One row, one whole year. The middle number is human years: 15 at year 1, 24 at year 2, then 4 more human years for every cat year after that. The right-hand word is the life stage for that birthday, using the 2021 AAHA/AAFP bands.
Year 15 is 76 human years and Senior. Count down the middle column and you will see a steady step of 4 after year 2. The stage word does not step every year. It stays on young adult through year 6, switches to mature adult at year 7, stays there through year 10, and becomes senior at year 11.
There is no row 0. A kitten under 1 year is not on this grid. The calculator will take months and will still call that cat a kitten.
Where the stage word changes
The bands are: young adult from 1 through 6, mature adult from 7 to 10, senior over 10. Year 6 and year 7 are neighbors in the grid and different stages. Year 10 and year 11 are the other cliff. A cat on their 10th birthday is still in the mature row. The day after that birthday is the senior side, which is why year 11 is the first senior row of whole years.
The definitions page says these cuts are arbitrary and that a fit cat over 10 may still be treated as a mature adult. The chart still marks the row. It does not overrule the vet who has examined that cat.
End of life is not a row at the bottom. It can happen at any year, so the grid does not add a final stage at 20.
A 15-year-old row, worked in place
Set the box to 15, which is how this page opens. Human years are 76 human years. The stage is Senior. Walk backward: year 2 is 24, and each of the thirteen years after that adds 4, which is 24 + 52 = 76. That arithmetic is the whole method. There is no second formula hiding in the senior rows.
If you only wanted the stage and not the human-year comparison, you can ignore the middle column and read the right-hand word. The two columns answer different questions, and this chart prints both so you do not have to guess which one a headline meant.
Cat years 1 to 20
| Cat year | Human years | Life stage |
|---|---|---|
| 1 | 15 | Young adult |
| 2 | 24 | Young adult |
| 3 | 28 | Young adult |
| 4 | 32 | Young adult |
| 5 | 36 | Young adult |
| 6 | 40 | Young adult |
| 7 | 44 | Mature adult |
| 8 | 48 | Mature adult |
| 9 | 52 | Mature adult |
| 10 | 56 | Mature adult |
| 11 | 60 | Senior |
| 12 | 64 | Senior |
| 13 | 68 | Senior |
| 14 | 72 | Senior |
| 15 | 76 | Senior |
| 16 | 80 | Senior |
| 17 | 84 | Senior |
| 18 | 88 | Senior |
| 19 | 92 | Senior |
| 20 | 96 | Senior |
Whole years. Human years are 15 at year 1, 24 at year 2, then 4 per year. Life stage follows the 2021 AAHA/AAFP bands: young adult through 6, mature adult from 7 to 10, senior after 10.
Tips and common mistakes
- Year 1 is young adult, not kitten. People often look for a kitten row and land on the wrong line.
- Do not multiply the cat's age by 7. That shortcut is not this chart.
- A 15-year-old and a 15-year-old plus four months are not the same. Only the whole year is a row.
When to call your vet
- The row says senior and you have not had an exam in many months. The definitions page asks for senior cats to be seen at least twice a year.
- Thirst, weight or the litter box changed. The row will not tell you why.
- You are choosing a food because the stage word changed between year 6 and year 7. Ask the clinic before you switch.
- The cat is under a year. Use the kitten weight and feeding pages, not row 1.
Frequently asked questions
What is a 15-year-old cat in human years?
- On the opening row of this page, year 15 is 76 human years and the stage is Senior. The step after year 2 is 4 human years per cat year.
When is a cat a senior?
After 10 years. Year 10 on this chart is still mature adult. Year 11 is the first whole year marked senior. A cat who is thriving can still be cared for as a mature adult if the vet says so.
How do you read the chart?
Find the year in the left column, read human years in the middle, and read the stage on the right. The middle column steps by 4 after year 2. The stage word changes only at year 7 and again at year 11.
Why is there no kitten row?
Kitten is under 1 year. This grid starts at the first birthday, which the definitions page already calls young adult. Months under 1 belong on the calculator.
Does the chart change for an indoor cat?
No. Indoor and outdoor are not columns. The human-year line and the stage marks are the same either way. Lifespan is not printed.