Dog Age Calculator
Dog years to human years, adjusted for size.
Everyday Tools
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Cat Age Calculator
Your cat's age in human years, and its life stage.
Cat Age Calculator tool
Optional.
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In human years
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Life stage
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Cat's age
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Each cat year now
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Typical lifespan
| Cat's age | In human years | Life stage |
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Cats age quickly for two years and then settle into roughly four human years for each of their own. The life stages here are the ones the American Association of Feline Practitioners uses, which is what most vets go by.
About the Cat Age Calculator
Cat Age Calculator converts a cat's age into human years and names the life stage it has reached. The arithmetic is simpler than a dog's because adult size barely matters: a maine coon and a siamese age at much the same rate once they have finished growing.
The first two years do most of the work. A cat reaches roughly the equivalent of fifteen human years by its first birthday and twenty-four by its second, because it has gone from newborn to fully grown adult in that time. After that, each year of a cat's life is worth about four human ones, which is why a seven-year-old cat is already middle-aged.
The life stages are the ones the American Association of Feline Practitioners defines, and they are more useful than the number. They mark when diet should change, when annual blood work starts being worth doing, and when weight loss or drinking more stops being a quirk and becomes something to mention to a vet. Indoor cats live substantially longer than cats with outdoor access, which is the single largest factor in the lifespan figure.
The page shows its working, not just its answer. Where there is a formula it is printed with your own numbers substituted in, so you can check the result rather than take it on trust -- which is the difference between a calculator you can use for something that matters and one you cannot.
Everything runs inside your browser. What you type is never uploaded, never logged and never stored, and the calculator keeps working if your connection drops after the page has loaded.
How to use the Cat Age Calculator
- Choose livesThe fields below change to match what you pick, so only the figures that matter to your case are asked for.
- Enter age in years and extra monthsDecimals are fine, and thousands separators are accepted and ignored.
- Read the in human years, life stage and cat's ageThe figures update as you type. The Calculate button is there if you would rather press something, but nothing waits for it.
- Copy or check the resultCopy the summary with the copy button, or open the table to check it row by row.
Features
- Shows in human years, life stage, cat's age, each cat year now and typical lifespan together, so you are not running it twice
- A results table you can read across
- Updates as you type, with no button to press and no page reload
- Copy the result in one click
- Free, no sign-up, and it runs entirely in your browser
Who uses this tool
The cat age calculator is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:
- Working out which life stage a cat has reached
- Knowing when senior blood work becomes worth doing
- Comparing a cat's age with a dog's or a person's
- Explaining to a child how old the cat really is
Frequently asked questions
How old is a one-year-old cat in human years?
About fifteen. A cat does most of its growing in the first year, which is why the first year counts for so much more than later ones.
When is a cat a senior?
From about eleven, which is roughly sixty in human years. Mature starts at seven and geriatric at fifteen.
Does breed change the answer?
Very little. Unlike dogs, cats of different breeds age at close to the same rate once they are adult.
Why do indoor cats live longer?
Traffic, fights, disease and predators account for most of the gap. The difference is large enough to be the main thing affecting how long a cat lives.
Related tools
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Checked and rebuilt on 2026-10-14. The method this calculator uses is described in the section above, and corrections go through the contact page.