Why isn't 1 dog year = 7 human years?

That rule of thumb was wildly inaccurate. Modern studies show dogs age much faster in their first two years, then slow down.

Do big dogs age faster?

Yes. Giant breeds typically age faster than small breeds — we adjust for that.

Yes — every FurTools tool is free forever, no signup required.

No. Everything runs in your browser and nothing is sent to our servers.

Estimate your dog's age in human years using a modern size-aware formula backed by veterinary research.

Dog age (years)

Size

In human years

Based on a medium dog, 3 year(s) old.