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Dog years to human years
Not the old "multiply by 7" rule — dogs mature fast early on, and bigger dogs age faster than smaller ones. This converter uses the size-based tables vets actually reference.
The chart, the method, and the common questions live on the full dog age calculator. Cat person? Cat years to human years.
What a dog's first year counts for in human years by the size-based veterinary guideline — not 7.
Dogs age differently by adult weight — small, medium, large and giant each get their own chart.
A 2-year-old cat in human years — cats race through their first two years, then add about 4 per year.
Aging tables: the size-class veterinary guideline commonly published by veterinary organizations.
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What's the catch?
There isn't one. Every calculator here is free, there's no signup, and nothing you type leaves your browser — the math runs on your device. No ads, and nothing about you or your pet is stored or sold. The site is run by one independent builder whose paid products cover the bills.
One rule keeps this site safe: no medication or toxicity calculators, ever — a wrong number could hurt an animal. For those questions, call your vet. Every number here is a guideline for intuition, and your vet knows your animal.
How this is calculated
The first dog year counts as about 15 human years and the second brings the total to about 24. After that, each year adds roughly 4–5 human years for small and medium dogs, and more for large and giant breeds. Between whole years, the converter interpolates.
Common questions
Isn't one dog year seven human years?
That old rule ignores how fast dogs mature early on and how differently sizes age. A one-year-old dog is roughly a teenager, not a seven-year-old child.
My dog is a mix — which size do I pick?
Go by adult weight: under 20 lb small, 21–50 lb medium, 51–90 lb large, over 90 lb giant. For a puppy, use the expected adult weight.
How seriously should I take the number?
It's a guideline for intuition, not a health measurement. Every dog ages differently — your vet knows your animal.
Who makes this
Built by one person, in the open.
PawNumbers is made by Jon, a product designer outside Chicago. He also runs Jon's Reminders, a text reminder service he built for his own parents.