How old is my cat in human years?

Cats age differently from dogs and humans. A 1-year-old cat is roughly 15 human years. A 5-year-old cat is about 36. Our calculator uses the AAHA/AAFP feline life stage guidelines.

How does cat age compare to human age by life stage?

The AAFP/AAHA feline life stage chart maps cat age to human age: a 6-month-old kitten ≈ 10 human years, a 1-year-old cat ≈ 15, a 2-year-old ≈ 24, a 5-year-old ≈ 36, a 10-year-old ≈ 56, a 15-year-old ≈ 76, and a 20-year-old ≈ 96. After age 3, each cat year adds approximately 4 human years. Senior cats (11+) benefit from biannual veterinary exams and blood work to catch age-related diseases like kidney disease, hyperthyroidism, and dental disease early.

What is the oldest cat ever recorded?

The oldest cat ever recorded was Creme Puff, a domestic shorthair from Austin, Texas, who lived to 38 years and 3 days (1967-2005), as verified by Guinness World Records. The oldest living cat on record (as of 2024) is Flossie, a 28-year-old British tortoiseshell. While these extreme ages are rare, indoor cats routinely live 18-25 years with excellent care. Key longevity factors include a strictly indoor lifestyle (outdoor cats average only 2-5 years), species-appropriate high-moisture nutrition, regular veterinary screening starting at age 7-8, dental care, maintaining a healthy weight, and environmental enrichment. The oldest recorded cats share common traits: indoor living, attentive owners who noticed health changes early, and consistent preventive veterinary care.

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Cat Age Calculator: Cat Years to Human Years

How old is your cat in human years? Based on official AAHA/AAFP 2021 Feline Life Stage Guidelines.

My cat's age in months

months

1 year = 12 months, 5 years = 60 months

Key Knowledge

How Cat Years Work

A 1-year-old cat ≈ 15 human years, year 2 adds 9, then 4 human years per cat year. A 10-year-old cat is ~56 human years. Cats age approximately 15 human years in their first year, 9 in their second year, and then 4 human years per cat year after that. A 3-year-old cat is ~28 human years; a 10-year-old cat is ~56; a 15-year-old cat is ~76. Unlike dogs, cat aging is relatively consistent across breeds (Siamese may live slightly longer).

Source: AAFP Feline Life Stage Guidelines

Cat Life Stages Defined by AAFP

AAFP defines 6 feline life stages: Kitten (0-6mo), Junior (7mo-2yr), Prime (3-6yr), Mature (7-10yr), Senior (11-14yr), Geriatric (15+yr). The American Association of Feline Practitioners (AAFP) defines six life stages: Kitten (0-6 months), Junior (7 months-2 years), Prime (3-6 years), Mature (7-10 years), Senior (11-14 years), and Geriatric (15+ years). Each stage comes with different nutritional, preventive care, and health screening recommendations.

Source: AAFP Feline Life Stage Guidelines (2021)

How Long Do Cats Live?

Indoor cats live 12-18 years on average (some reach 20+); outdoor cats average 2-5 years due to traffic, predators, and disease. Indoor cats live 12-18 years on average; some reach 20+. Outdoor cats average 2-5 years due to traffic, predators, and disease. Well-cared-for indoor cats in their late teens are common. The oldest recorded cat (Creme Puff, Texas) lived 38 years. Genetics, diet, preventive care, and indoor lifestyle are the strongest longevity predictors.

Source: ISFM Feline Care Guidelines

Senior Cat Health Screening

AAFP recommends annual blood work from age 7-8, biannual exams at 11+, and more frequent monitoring at 15+ for cats. AAFP recommends: annual blood work starting at age 7-8 (Mature stage), biannual exams at 11+ (Senior), and more frequent monitoring at 15+ (Geriatric). Key screens include: CBC, biochemistry panel, urinalysis, T4 (thyroid), and blood pressure. Cats hide illness — regular screening catches kidney disease, hyperthyroidism, and diabetes early.

Source: AAFP Senior Care Guidelines

Data verified by petsMetrics using peer-reviewed veterinary sources. Citations: ASPCA, AVMA, AAFP. Last reviewed: 2026.

The Science Behind the Cat Age Calculator

Our calculator follows the AAFP/AAHA Feline Life Stage Guidelines (2021), which establish a non-linear aging curve: 15 human years for the first cat year, 9 for the second, and 4 per year thereafter. This model is based on feline physiology studies comparing organ maturation rates, reproductive maturity timelines, and age-related disease incidence curves between cats and humans. The six life stages (Kitten through Geriatric) each carry specific health screening frequencies benchmarked to AAFP and ISFM clinical recommendations.

References: AAFP Feline Life Stage Guidelines (2021); ISFM Guidelines on Feline Aging— via petsMetrics

Track Your Cat's Health Over Time

Now that you know your cat's life stage, use our BCS Weight Tracker to monitor their body condition and ensure they stay at a healthy weight at every age.

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