Cat Age Calculator (Human Years)

AGE CALCULATOR CAT PETS
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Cat age calculator. Reads the published cat-to-human age chart (2010 AAFP-AAHA guidelines; International Cat Care) month by month to 25 years, with the 2021 AAHA/AAFP life stage.

RT-PET-002 · Pets & Animals
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Cat Age

Up to 25 years, where the published charts stop. For a kitten, leave years at 0 and enter months.

📅 Research current as of 12 Oct 2026 · Sources: 2010 AAFP–AAHA and 2021 AAHA/AAFP Feline Life Stage Guidelines; International Cat Care age chart
Standards, published formulas, and reference data are revised over time — check against a current authoritative source before relying on these figures.
🐾 Always confirm with your veterinarian. The human-age figure is a reading from a published chart, a way of talking about a cat's age, not a measure of its health. For anything about your own cat, ask your vet.
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How to use the cat age calculator

Enter your cat's age in years and months

For a kitten, leave years at 0 and enter months. The calculator reads the chart up to 25 years, the last row either published chart prints; it will not go past that, and it asks again if the box is blank.

Read the human-equivalent figure

Where your cat's age is a row of the chart, you get that row as printed: 6 months is 10, 1 year is 15, 2 years is 24, then 4 more for each year, so 5 years is 36 and 15 years is 76. Between two rows, the calculator reads in a straight line and says so, marking the figure "about".

Compare the 2010 chart

The 2010 AAFP–AAHA chart and International Cat Care's agree from 6 months on. In the first months the 2010 chart prints ranges (2–3 months: 2–4; 4 months: 6–8), and the calculator shows those beside the reading.

See the 2021 life stage

The stage shown is from the 2021 AAHA/AAFP guidelines: kitten up to 1 year, young adult 1 through 6, mature adult 7 to 10, senior over 10. The calculator reads "over 10" literally, so a cat becomes senior once it is older than exactly 10. The guidelines add a fifth stage, end of life, which can come at any age, so it is not assigned by age here.

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Cat years: a 2010 chart and the 2021 life stages

Where the chart comes from

The usual answer to "how old is my cat in human years" is a chart: 15 at the first birthday, 24 at the second, then 4 for every year after, up to 25 years at 116. The earliest printing of it we could open is a box in the 2010 AAFP–AAHA Feline Life Stage Guidelines (Hoyumpa Vogt A, Rodan I, et al. J Am Anim Hosp Assoc 2010;46:70–85, PDF at aaha.org). The guidelines credit their six life stages to the Feline Advisory Bureau; they give no study, data or method for the human-age column. International Cat Care, which was the Feline Advisory Bureau until it was renamed (its history page), publishes the same numbers today, with a row for each month to 7 months (icatcare.org).

None of the veterinary documents we opened uses "one cat year equals seven human years", and we could not trace where that rule comes from.

The 2021 guidelines dropped the human column

The current AAHA/AAFP Feline Life Stage Guidelines (Quimby J et al. J Am Anim Hosp Assoc 2021;57(2):51–72, PDF at aaha.org) define life stages only: kitten, from birth up to 1 year; young adult, 1 through 6 years; mature adult, 7 to 10 years; senior, over 10 years; and an end-of-life stage that can occur at any age. AAHA and the AAFP reduced the 2010 scheme's six stages (kitten, junior, prime, mature, senior and geriatric) to these four plus end of life. There is no geriatric stage in their 2021 scheme, and no table of human ages. International Cat Care still describes six life stages.

"Any age groupings are inevitably arbitrary demarcations along a spectrum and not absolutes." — Quimby J et al., 2021 AAHA/AAFP Feline Life Stage Guidelines, JAAHA 57(2), p. 53.

Kittens: the chart is not a straight line

The chart packs most of the first year into the first months: 6 months is 10 and 7 months is 12, then only 3 more to reach 15 at a year. A calculator that spreads the first year evenly at 15 a year (as this one did before October 2026) reads 7 months as under 9. This calculator follows the chart's rows instead. In the first months the two published charts differ in precision, not in substance: the 2010 chart gives 2–4 for 2 to 3 months and 6–8 for 4 months, and International Cat Care gives single figures, 2, 4 and 6, each inside the 2010 range.

How the chart compares with how long cats live

The chart is a convention, not a survival table. In UK life tables built from 7,936 deaths of cats under primary veterinary care, life expectancy at birth was 11.74 years (Teng KTY et al. J Feline Med Surg 2024;26(5), doi:10.1177/1098612X241234556). An earlier English study of about 4,000 deaths found a median longevity of 14.0 years (O'Neill DG et al. J Feline Med Surg 2015;17(2):125–133, PMC10816413). On the chart, a 14-year-old cat is 72. Singapore's resident life expectancy at birth was 83.7 years in 2024 (SingStat complete life tables). Both cat studies are of UK cats; we found no life table for cats in Singapore or Malaysia.

Cats in Singapore

Singapore began licensing pet cats in September 2024 under its Cat Management Framework. On 18 July 2026 NParks reported about 66,000 pet cats licensed since the scheme started, with the transition period ending on 31 August 2026 (NParks).

Where the cat-years chart came from, and what the 2021 guidelines kept

01

The chart: 15 at 1 year, 24 at 2, then +4 a year, to 116 at 25.

02

Earliest printing we could open: the 2010 AAFP–AAHA Feline Life Stage Guidelines, which give no method for it.

03

The 2021 AAHA/AAFP guidelines have no human-age column at all.

04

2021 stages: kitten to 1, young adult 1–6, mature adult 7–10, senior over 10, plus end of life at any age.

05

The 2010 scheme had six stages, including prime (3–6) and geriatric (15+). 2021 has neither.

06

On the chart, 6 months is 10 and 7 months is 12: most of the first year comes in the first months.

07

At 4 months the 2010 chart prints a range, 6–8; International Cat Care prints 6, inside it.

08

UK cats under vet care: life expectancy at birth 11.74 years (Teng 2024); median longevity 14.0 (O'Neill 2015).

09

Guinness lists Creme Puff (Austin, Texas) as the oldest cat ever: 38 years and 3 days.

10

Singapore began licensing pet cats in September 2024; NParks reported about 66,000 licensed by July 2026.

Frequently asked questions

  • Not on any veterinary chart we opened. The 2010 AAFP–AAHA chart and International Cat Care's give 15 for the first year, 24 by the second birthday and 4 a year after that. We could not trace where the seven-year rule for cats comes from.

  • The earliest printing we could open is the 2010 AAFP–AAHA Feline Life Stage Guidelines. They give no method or data for the human-age numbers. The 2021 revision left the human column out and kept only life stages. International Cat Care still publishes the same chart.

  • Spreading the first year evenly at 15 a year reads 6 months as 7.5. The published charts give 10 at 6 months and 12 at 7 months. This calculator returns the chart's row where there is one and reads in a straight line between rows, marking those figures "about". At 2 to 4 months the 2010 chart prints ranges where International Cat Care prints single figures inside them, and the calculator shows both.

  • Both published charts stop at 25 years (116). We do not extend a chart past its last printed row. Cats do live longer: Guinness lists Creme Puff at 38 years and 3 days, and the ageing study by Raj K et al. (GeroScience 2021, PMC8599556) gives 30 years as the maximum confirmed lifespan in the AnAge database.

  • The 2021 AAHA/AAFP Feline Life Stage Guidelines define senior as over 10 years, and say a senior cat in excellent condition may be treated as a mature adult at the vet's discretion. The 2021 AAFP Feline Senior Care Guidelines add that some cats may be more appropriately called senior as early as 8. Your vet decides for your cat.

  • Two 2021 documents do not give the same interval for a 7- to 10-year-old. The joint AAHA/AAFP Feline Life Stage Guidelines (Table 4) list diagnostics every 1–2 years for a mature adult (7–10) and at least yearly, every 6 months recommended, for a senior, as the task force's opinion for apparently healthy cats. The AAFP Feline Senior Care Guidelines (Ray M et al. J Feline Med Surg 2021;23(7), PMC10812122) say to consider baseline diagnostics at least annually, starting at age 7–10 years, with frequency increasing with age. We report both; your vet decides what applies to your cat.

  • In the 2024 UK life tables (Teng et al.), Burmese (14.42 years) and Birman (14.39) had the longest life expectancy at birth of the breeds analysed and Sphynx the shortest (6.68, from 18 deaths). Crossbred cats were 11.89, Siamese 11.69, Ragdoll 10.31, Maine Coon 9.71 and Russian cats 9.65 (19 deaths). In the same study, purebred cats had 1.83 times the odds of dying before age 3 that crossbreds had. The 2015 English study (O'Neill et al.) also found crossbreds lived longer than purebreds as a group, median 14.0 against 12.5 years. Several breeds rest on few deaths, so their figures are uncertain, and both studies are of UK cats.

  • If anything about your cat's behaviour changes, ask your vet. Vets can score pain from a cat's face with the Feline Grimace Scale, published by researchers at the Université de Montréal's veterinary faculty (Evangelista MC et al. Sci Rep 2019, doi:10.1038/s41598-019-55693-8).

  • No. All inputs stay in your browser.

  • No. It reads a published chart and names a published life stage. It says nothing about your cat's health; for that, ask your vet.

Method & sources

How it computes

Reads International Cat Care's published chart: 2, 4, 6, 8, 10, 12 at 2-7 months, 15 at 1 year, 21 at 18 months, 24 at 2 years, then 4 a year to 116 at 25. The 2010 AAFP-AAHA guidelines print the same chart with no stated method, and ranges at 2-4 months, shown alongside. Between rows: a straight line, marked "about". Blank input or over 25 years: refused. Life stage: 2021 AAHA/AAFP guidelines, which have no human-age column.

What this tool implements

  • The human-age figure is a reading of a published chart, not a measurement of a cat's health or biology. The earliest printing of the chart we could open is the 2010 AAFP-AAHA Feline Life Stage Guidelines, which give no study, data or method for the human-age column. The 2021 AAHA/AAFP revision has no human-age column.
  • Chart rows are returned as printed. Between rows the calculator reads in a straight line and marks the figure "about". Where the 2010 chart prints a range (2-3 months: 2-4; 4 months: 6-8) it is shown beside the International Cat Care reading; from 6 months on the two charts agree.
  • Corrected 2026-10-12: year one was computed as 15 x age and year two as 15 + 9 x (age - 1), which ran below both published charts all through kittenhood, by up to 3.25 human years (7 months: 8.75 against 12).
  • Blank, non-numeric, negative and over-25-year ages are refused; both charts stop at 25 years (116) and the calculator does not extend them. Until 2026-10-12 a blank age was read as 5 years and there was no upper limit.
  • Life stage per the 2021 guidelines: kitten up to 1 year, young adult 1 through 6, mature adult 7 to 10, senior over 10, read literally (older than exactly 10). End of life can occur at any age and is not assigned. The 2010 stage names Prime and Geriatric are not used for 2021 stages.
  • No veterinary advice. Where the page mentions routine testing it reports the two 2021 AAFP documents as each states it, attributed, and refers the reader to a vet.

Sources

Abridged — the full review record for this tool runs longer than the list above.

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