Breed lifespan from RVC VetCompass data, plus how many years your cat likely has left
Cats live 11.7 years on average at birth in the RVC's 2024 VetCompass study of UK veterinary records, with crossbreds at 11.9. Breed moves the number a lot: Burmese and Birman reach 14.4 years, while Sphynx average just 6.7. US vets commonly cite 13–17 years for indoor pet cats versus 2–5 for outdoor-only cats, because those figures describe cats that survived kittenhood. This calculator adjusts the breed number for sex and body weight, then estimates years remaining from your cat's age. The levers you control: weight (each extra 100 g costs about 0.02 years) and keeping outdoor access supervised.
| Lifestyle | Commonly Cited Lifespan | What It Means |
|---|---|---|
| Indoor only | 13 – 17 yrs | Standard US veterinary citation for established house cats |
| Indoor-outdoor mix | Not significantly different from indoor | UC Davis feline longevity study found no significant penalty for mixed access |
| Outdoor only, free-roaming | 2 – 5 yrs | Traffic, predators, and exposure dominate; widely cited, hard to trace to one study |
| At birth, all lifestyles (RVC 2024) | 11.7 yrs avg | UK VetCompass data counting every death, including kittens |
Why the gap between 11.7 and 13–17? Life expectancy at birth averages in every early death, kitten mortality included. Figures like "indoor cats live 13–17" follow cats that already made it to adulthood and into a home. Both are honest, they just answer different questions.
| Breed | Life Expectancy | Versus Crossbred (11.9) | Typical Ideal Weight |
|---|---|---|---|
| Burmese | 14.4 yrs | +2.5 | 8 – 12 lb |
| Birman | 14.4 yrs | +2.5 | 8 – 12 lb |
| Crossbred (domestic) | 11.9 yrs | baseline | 8 – 12 lb |
| Siamese | 11.7 yrs | −0.2 | 8 – 10 lb |
| British Shorthair | 11.7 yrs | −0.2 | 9 – 17 lb |
| Persian | 10.9 yrs | −1.0 | 7 – 12 lb |
| Ragdoll | 10.3 yrs | −1.6 | 10 – 20 lb |
| Maine Coon | 9.7 yrs | −2.2 | 10 – 25 lb |
| Bengal | 8.5 yrs | −3.4 | 8 – 15 lb |
| Sphynx | 6.7 yrs | −5.2 | 6 – 12 lb |
From the Royal Veterinary College's 2024 VetCompass life tables (Teng et al., Journal of Feline Medicine and Surgery), built on UK veterinary records of cats that died 2019–2021. Females average 11.9 years versus 11.2 for males, and crossbreds outlive purebreds by about 1.27 years on average.
Life expectancy is the middle of a distribution, not a date. This tool starts from your breed's published life expectancy at birth, adjusts for the two factors the RVC study quantified, and reports years remaining as a range-shaped honest estimate.
Start with the breed's life expectancy at birth. Adjust for sex: females +0.2 years, males −0.5, matching the study's population averages. Then the weight effect: lifespan falls about 0.02 years per 100 g that a cat carries above its breed's typical ideal weight, computed from the weight you enter. Years remaining is that adjusted expectancy minus current age.
Pick the closest breed, a domestic shorthair or longhair is a crossbred, and enter age and current weight. Weigh honestly: owners underestimate cat weight by wide margins, and indoor cats creep upward on free-fed dry food. The weight tile shows exactly what those extra pounds cost in expectancy.
A 4-year-old female domestic shorthair at 14 lb. Baseline is 11.9 years, sex adds 0.2, and the 4 lb over a typical 10 lb ideal (about 1,814 g, or 18 units of 100 g) subtracts 0.36. Adjusted expectancy: 11.9 + 0.2 − 0.36 = 11.7 years, leaving about 7.7 typical years. Getting her to 11 lb would buy back 0.27 of those years, plus whatever quality-of-life comes with it.
Same cat as a Sphynx male: baseline 6.7, sex −0.5, and the 6 lb over an 8 lb ideal subtracts another 0.54. Adjusted expectancy: 5.7 years, about 1.7 typical years remaining at age 4. The breed table dominates everything else, which is the Sphynx's heart-disease problem (hypertrophic cardiomyopathy) showing up in actuarial form.
Distributions have long right tails, cats are famously long-lived at the top of them, and a cat who reaches 15 has already exited the table's jurisdiction (vets commonly see these cats reach 17–20). Use the estimate for planning, when to start senior screening, whether pet insurance still pencils out, not as a countdown. To translate your cat's age into human terms, the cat age calculator uses the 15/9/4 conversion, and the pet insurance calculator prices the accident-and-illness coverage question.
The RVC's 2024 VetCompass study of UK veterinary records puts average life expectancy at birth at 11.7 years, with crossbred cats at 11.9. US veterinary sources commonly cite indoor pet cats at 13-17 years because those figures describe cats that survived kittenhood and stay indoors. Both numbers describe the same animals differently, one counts every death, the other follows established house pets.
US veterinary sources commonly cite 2-5 years for free-roaming outdoor cats versus 13-17 indoors, a gap of roughly a decade. UC Davis researchers found cats with mixed indoor-outdoor access did not differ significantly from indoor-only cats, so the penalty concentrates on outdoor-only cats. The outdoor figure is hard to trace to a single study, but it's the standard citation across veterinary medicine.
In the RVC's 2024 breed table, Burmese (14.4 years) and Birman (14.4) lead, followed by Siamese and British Shorthair (11.7). The shortest expectancies belong to Sphynx (6.7 years) and Bengal (8.5). Crossbreds average 11.9, about 1.27 years longer than purebreds overall, so the moggie from the shelter is a good longevity bet.
Three levers with evidence behind them. Weight: the RVC study found lifespan drops about 0.02 years for every 100 g of body weight, so keeping a cat lean matters more than most supplements. Neutering was associated with longer life in the same data. And annual vet visits catch kidney disease, hyperthyroidism, and dental disease early, the three chronic conditions that quietly shorten cat lives.
A 15-year-old cat has already beaten the at-birth average, which means the tables no longer describe her. Cats who reach 15 commonly live to 17-20. At this age the useful questions shift from expectancy to quality: weight trend, hydration, and mobility, all of which your vet reads better than any life table.