Dog Age Calculator
Convert your dog's age into human years using the modern size-based method instead of the old times-seven rule.
Small dogs (under ~20 lb) age slower late in life; giant breeds (over ~90 lb) age fastest. The first two years count for the most human years no matter the size.
How it works
The famous "one dog year equals seven human years" is a myth. Dogs mature fast early on, then age more gently, and the pace depends heavily on size — small breeds outlive giant ones by years.
This uses the more realistic modern approach: the first two years count for a lot of human equivalent, and each year after that adds an amount that grows with the dog's size, from small up to giant.
Pick your dog's size and enter its age, and you get a human-equivalent number that lines up far better with how dogs actually age than any single multiplier could.
Frequently asked questions
Is one dog year really seven human years?
No. That old rule oversimplifies. Puppies age very quickly at first, and larger breeds age faster overall, so a proper estimate depends on both age and size.
Why do small dogs live longer than big dogs?
Large and giant breeds grow fast and their bodies wear out sooner, so they age more quickly in later life. A small dog's later years pass more slowly in human terms.
How is the first two years counted?
The first year of a dog's life is worth roughly 15 human years and the second adds about nine more, because dogs reach adulthood quickly before the pace settles down.