Cat Age Calculator
Convert your cat's age to human years using the AAHA-adjusted formula. Find your cat's life stage, vet schedule, vaccination timeline, and daily calorie needs.
yrs
Human Equivalent Age
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Life Stage —
Next Life Stage —
Extended More scenarios, charts & detailed breakdown ▾
yrs
Human Equivalent Age
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Life Stage —
Human Life Stage Equivalent —
Professional Full parameters & maximum detail ▾
Age & Stage
Human Equivalent Age —
Life Stage —
Life Expectancy —
Health & Nutrition
Weight for Life Stage —
Daily Calorie Need —
Ideal Weight Range —
How to Use This Calculator
- Enter your cat's age in years (decimals OK — e.g., 0.5 for 6 months).
- See the human equivalent age and life stage instantly.
- Use Human to Cat tab to find the cat equivalent of your own age.
- Use Health Milestones to get vet visit schedule and vaccination reminders.
- Use the Professional tab for calorie needs, weight assessment, and life expectancy.
Formula
Year 1: 1 cat year = 15 human years
Year 2: +9 human years (total 24)
Year 3+: each cat year = 4 human years
Example
Example: 5-year-old cat → 24 + (5−2) × 4 = 24 + 12 = 36 human years (Adult stage).
Frequently Asked Questions
- The AAHA formula: Year 1 = 15 human years, Year 2 = +9 years (total 24), then each additional year = +4 human years. A 5-year-old cat is approximately 36 in human years.
- No — the 7:1 rule is oversimplified. Cats age very rapidly in their first two years (reaching human adulthood equivalent by age 2) then age more slowly afterward.
- Kitten (0–1 yr), Junior (1–2 yrs), Adult (2–7 yrs), Mature Adult (7–10 yrs), Senior (10–15 yrs), Geriatric (15+ yrs). These stages guide veterinary care recommendations.
- Indoor cats typically live 12–18 years, with an average of 15 years. Outdoor cats live shorter lives — 10–14 years on average — due to traffic, predators, and disease exposure.
- Cats are considered senior at age 7 (equivalent to about 44 human years). At this stage, bi-annual vet exams are recommended with bloodwork to screen for kidney disease, hyperthyroidism, and diabetes.