Dog age in human years, by breed
Breed size is the single biggest factor in how fast a dog ages. A ten-year-old Chihuahua is roughly 56 in human years; a ten-year-old Great Dane is roughly 88. Same birthday, 32 human years apart.
Most age calculators apply one formula to every dog. These pages don't — each breed uses the ageing curve for its actual weight class, alongside that breed's published lifespan and the health conditions that shape how it ages.
Small (under 20 lb / 9 kg) — 4 human years per dog year
French BulldogMiniature PoodleDachshundYorkshire TerrierCavalier King Charles SpanielMiniature SchnauzerShih TzuBoston TerrierPomeranianHavaneseShetland SheepdogPugChihuahuaMalteseWest Highland White TerrierBichon FriseJack Russell Terrier
Medium (21–50 lb / 10–23 kg) — 5 human years per dog year
BulldogBeaglePembroke Welsh CorgiAustralian ShepherdBrittanyCocker SpanielBorder CollieBasset HoundShiba InuWhippetAustralian Cattle DogEnglish Springer Spaniel
Large (51–100 lb / 23–45 kg) — 6 human years per dog year
Labrador RetrieverGolden RetrieverGerman ShepherdPoodleRottweilerGerman Shorthaired PointerBoxerDoberman PinscherSiberian HuskyVizslaWeimaranerCollieRhodesian RidgebackAkitaSamoyedGoldendoodleLabradoodleDalmatianChow ChowAmerican Pit Bull Terrier