Dog Life Expectancy by Size
Small dogs have a median lifespan of 12.7 years, medium dogs 12.5 years, and large dogs11.9 years, according to a 2024 study of 584,734 dogs under UK veterinary care. Pick your dog's size below for the full figures, including the age by which 95% of dogs in that group have died.
All three sizes
| Size | Median lifespan | 95% have died by | Dogs in study |
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Where this comes from, and what "size" means here
Data from McMillan KM, Bielby J, Williams CL, Upjohn MM, Casey RA, Christley RM. "Longevity of companion dog breeds: those at risk from early death." Scientific Reports 14, 531 (2024), reused underCC BY 4.0from PMC10834484. The paper classifies each breed into small, medium, or large based on its own breed-standard weight bands, not a single universal cutoff — this tool doesn't ask for your dog's weight because that breed-to-category mapping isn't something we're reproducing here. If you know your dog's breed, thebreed-level lookupis more specific than the size category alone.