The conversion is non-linear. A 1-year-old cat = approximately 15 human years. A 2-year-old cat = approximately 24 human years. From age 2 onwards, each additional cat year adds approximately 4 human years. So a 10-year-old cat ≈ 56 human years (24 + 8×4 = 56). This formula is endorsed by the ISFM (International Society of Feline Medicine) and is more accurate than the old "multiply by 7" myth.
The average lifespan of a domestic cat in the UK is 12 to 15 years, according to PDSA PAW Report data. Indoor cats typically live longer (12–18 years average) than outdoor cats (10–14 years), as they face lower risks from road accidents and infectious diseases. Neutered cats also tend to outlive unneutered cats by an average of 2–3 years. Many modern cats reach their late teens with good veterinary care and nutrition.
The oldest cat ever recorded was Creme Puff, from Austin, Texas, who lived for 38 years and 3 days (1967–2005), holding the Guinness World Record. In human equivalent years, 38 cat years equates to approximately 169 human years using the standard non-linear formula. In the UK, cats regularly living beyond 20 years are documented, though such longevity remains exceptional.
From age 7, vets and the RSPCA recommend health checks every 6 months rather than annually. Senior cats are at higher risk for kidney disease, hyperthyroidism, high blood pressure, arthritis, and dental disease. Standard senior screening includes blood pressure measurement, T4 thyroid test, kidney function panel (urea, creatinine, SDMA), and urine analysis. From age 11, 6-monthly screens should also assess cognitive function and pain levels.
The ISFM defines six feline 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 has distinct nutritional, veterinary, and behavioural needs. Our calculator identifies which stage your cat is currently in and provides relevant care information for that life phase.
According to the PDSA PAW Report 2023, there are approximately 11.8 million cats kept as pets in the UK — making them the second most popular pet after dogs. Around 24% of UK adults own a cat. The UK is one of Europe's largest cat-owning nations. Since June 2024, microchipping has been compulsory for cats in England under the Microchipping of Cats and Dogs (England) Regulations 2023.
UK vets recommend first vaccinations at 8–9 weeks of age, with a second dose at 12 weeks. Core vaccines protect against feline herpesvirus, calicivirus, and panleukopenia (feline parvovirus). The FeLV (feline leukaemia virus) vaccine is recommended for cats with outdoor access. Annual booster vaccinations are required to maintain immunity. Your vet will provide a vaccination record booklet — keep this safe as it may be needed for catteries or travel.