Cat Age Calculator
Based on the AAFP/AAHA Feline Life Stage Guidelines. Far more accurate than the old "cat year = 7 human years" shortcut — cats age extremely fast in their first two years, then slow dramatically.
Equivalent human age
28 years
≈ human age for a 3.0-year-old indoor cat
How the cat age formula works
The AAFP/AAHA guidelines divide cat ageing into stages:
- 0–1 year — Kitten. Equivalent to 0–15 human years (puberty by 6 months).
- 1–2 years — Young adult. Year 2 adds ~9 human years.
- 3–6 years — Mature. Each year adds ~4 human years.
- 7–10 years — Senior. Same ~4 per year; annual vet checks with bloodwork start here.
- 11+ years — Geriatric. 6-monthly vet checks recommended.
Why lifestyle matters
Indoor cats live 12–20 years on average. Outdoor-roaming cats in Australia average 3–5 years shorter due to traffic, predator injuries, FIV/FeLV exposure, and environmental hazards. Indoor-outdoor is in between.
When to step up vet visits
- Kitten (under 1): boosters at 6, 9, 12 weeks; desex by 4 months.
- Young adult (1–6): annual check + vaccines.
- Senior (7–10): annual bloodwork + urine.
- Geriatric (11+): 6-monthly check + bloodwork + urine + blood pressure.
Not veterinary advice. Ageing estimates are approximate for individual cats.