Cat age calculator
Enter your cat age, see it in human years.
How old is my cat in human years?
By the American Veterinary Medical Association chart: 15 at age 1, 24 at age 2, then 4 human years for each cat year — 40 at 6, 56 at 10 and 80 at 16.
Why does the first year count as 15?
The AVMA chart puts most of the aging early: 15 human years in the first year and 9 more in the second, then 4 a year.
Is a cat year seven human years?
No — that rule does not match the AVMA chart at any age.
What about ages between whole years?
The calculator reads between chart rows in a straight line: 6½ years is about 42.
How accurate is it?
It is an approximation. The AVMA suggests asking your veterinarian about your own cat.
Worked example: three cats compared with the seven-year rule
Between rows the calculator moves in a straight line. A cat of 3½ lies halfway between the 3-year row (28) and the 4-year row (32), so its human age is 30. A 12-year-old cat is 64 on the chart, where the old rule of 7 would say 84. A 16-year-old is 80 on the chart against 112 by the rule. The two methods differ most at both ends of life: a 1-year-old cat is 15 on the chart but 7 by the rule.
Are the chart’s years the same as veterinary life stages?
Not quite. Veterinary guidelines group a cat’s life into stages rather than into human-equivalent years. The 2021 AAHA/AAFP Feline Life Stage Guidelines use four age-related stages (kitten, young adult, mature adult and senior) plus an end-of-life stage, replacing the six stages of the 2010 version. The 2010 edition already noted that life stages in cats are not well defined: individual animals and body systems age at different rates, and any grouping by age is an arbitrary demarcation along a spectrum. A human-years figure is a conversation aid, and the stage and the individual cat’s health matter more for care.
Which life stage is my cat in, and how often should it see the vet?
The 2021 AAHA/AAFP guidelines give the age bands as kitten (birth up to 1 year), young adult (1 to 6 years), mature adult (7 to 10 years) and senior (10 years and older), with an end-of-life stage at any age. On the AVMA chart those bands correspond to roughly 15 to 40 human years for a young adult, 44 to 56 for a mature adult, and 56 and up for a senior. The guidelines advise a full physical examination at least once a year for cats of every stage and checkups at least every six months for senior cats. The bands and the chart come from different sources and are not designed to match, so read them side by side only as a rough guide.
What about cats older than 16?
The AVMA chart stops at 16 years, so this calculator does too, and it shows a message instead of a guess beyond the table. Extending the 4-years-per-year pattern is a simple extrapolation, not a figure from the chart, and individual cats vary a great deal at that age.
Common mistakes with cat ages
Entering months as years: 18 months is 1.5, not 18. Using the calculator for a kitten under a year old, since the AVMA chart starts at age 1 and the calculator shows no value below it. Applying the dog chart to a cat: the AVMA medium-dog row and the cat row agree for the first five years and then diverge. Multiplying by 7. And treating a human-equivalent age as a medical measure: it does not show how healthy an individual cat is, which is a question for your veterinarian.
Sources and related calculators
Sources: American Veterinary Medical Association, “Pets age faster than people” (cat and dog chart); “2021 AAHA/AAFP Feline Life Stage Guidelines,” Journal of Feline Medicine and Surgery 23(3) and Journal of the American Animal Hospital Association 57(2); “AAFP-AAHA: Feline Life Stage Guidelines,” Journal of Feline Medicine and Surgery (2010). Related: dog age calculator, pet calorie calculator and age calculator.