Cat Age Calculator

Cats age much faster in their early years. Enter your cat's age in years and months to see the equivalent human age and life stage, using the ISFM feline age scale.

Cat Age — Years

+ Months

ISFM Cat Age Reference Table

Cat Age	Human Equivalent	Life Stage
0–6 months	0–10 years	🐣 Kitten
7–12 months	10–15 years	🐈 Kitten/Junior
1–2 years	15–24 years	🐾 Junior
3–6 years	28–40 years	😺 Prime Adult
7–10 years	44–56 years	🦴 Mature
11–14 years	60–72 years	🧓 Senior
15+ years	76+ years	👴 Super Senior

Cat Age to Human Years Calculator – How Old Is Your Cat in Human Years?

Cats age at a fundamentally different rate to humans, and the popular rule of multiplying by seven (which people sometimes apply to dogs) does not apply to cats at all. Cat aging is heavily front-loaded: a one-year-old cat has already developed into a young adult physically and sexually, equivalent to a human in their mid-to-late teens. A two-year-old cat is roughly equivalent to a person in their mid-twenties. After the second year, the progression slows to approximately four human years for every single cat year. This free cat age calculator converts your cat's age into the human equivalent using current veterinary guidelines, so you understand their life stage and can provide the right level of care at every point in their life.

How Do Cats Age Compared to Humans?

Cat aging follows a non-linear curve that surprises most people. Based on guidelines from the International Cat Care organisation and current veterinary consensus:

First year — Equivalent to approximately 15 human years. A kitten transitions from helpless newborn to sexually mature young adult within 12 months.
Second year — Adds roughly another 9 human years. By age two, a cat is developmentally equivalent to a human in their mid-twenties.
Year 3 onwards — Each additional year adds approximately 4 human years. A 10-year-old cat is roughly 56 in human terms. A 15-year-old cat is around 76.

Cats who reach their late teens and early twenties are genuinely comparable to human centenarians — exceptional longevity that requires extraordinary care and attention.

Cat Life Stages and What They Mean for Care

Understanding your cat's life stage is the foundation of providing the right care:

Kitten (0–6 months) — Rapid growth phase. Needs kitten-formulated food rich in protein and fat. Highly energetic and playful. Vaccinations, microchipping, and neutering typically happen in this period.
Junior (7 months – 2 years) — Physically maturing and reaching full adult size. Still playful and curious. Annual vet check-ups begin here.
Prime adult (3–6 years) — Peak health and activity. Stable and confident. Needs consistent nutrition, enrichment, and yearly health checks.
Mature (7–10 years) — The cat equivalent of middle age. May begin slowing down slightly. Worth switching to a mature or indoor formula if lifestyle has become more sedentary.
Senior (11–14 years) — Increased risk of age-related conditions including kidney disease, hyperthyroidism, arthritis, and dental disease. Twice-yearly vet visits are recommended at this stage.
Geriatric (15+ years) — Exceptional longevity. Requires close monitoring, gentle handling, and highly palatable food as appetite and digestion often change significantly.

How to Use the Cat Age Calculator

Enter your cat's age in years. Add months for a more precise result if your cat is less than three years old.
The calculator instantly displays the human age equivalent.
Your cat's current life stage is shown alongside care guidance relevant to that stage.

How to Keep Your Cat Healthy at Every Age

Feed an age-appropriate diet — kitten food for cats under 12 months, adult formulas during prime years, and senior diets for cats over 10
Schedule annual health checks for adults and twice-yearly for seniors and geriatric cats
Keep up with vaccinations, flea treatment, and regular worming
Provide mental stimulation through play sessions, puzzle feeders, and vertical climbing space
Monitor body weight monthly — unexplained weight loss in older cats is one of the earliest signs of hyperthyroidism or kidney disease
Keep the litter tray clean and accessible — senior cats with arthritis need easier access than young cats

Knowing your cat's human-equivalent age puts their health and behavior in far better perspective. A 13-year-old cat that is sleeping more than usual is the equivalent of a person in their late sixties — entirely natural, and a useful signal to increase the frequency of health monitoring and ensure their environment stays comfortable and low-stress.