Dog to Human Years Calculator

A 1-year-old dog is sexually mature and roughly equivalent to a 15-year-old human, not a 7-year-old. The 7x rule was a rough average that doesn't account for the rapid growth in a dog's first two years. Modern veterinary science uses a logarithmic model that better reflects how dogs actually age.

This is one of biology's great mysteries — it's the opposite of what we see between species (elephants outlive mice). Larger dogs may age faster due to higher growth rates increasing oxidative damage, or because their bodies simply wear out faster from supporting more mass. A Chihuahua might live 15-20 years while a Great Dane averages 7-10.

The oldest verified dog was Bobi, a Portuguese Rafeiro do Alentejo who lived to 31 years and 165 days (2023). Using our formula, that's approximately 200+ human years! Before Bobi, the record was held by Bluey, an Australian Cattle Dog who lived to 29 years and 5 months.