PetYearsHow old is your pet in human years?
Slide to your pet’s age for their human-year equivalent, life stage, and expected lifespan — using real, size-aware veterinary curves, not the old “multiply by 7” myth.
Size-aware estimate based on the AKC dog-age chart & veterinary life-stage guidance. A guide, not a diagnosis.
🐾 Size-aware, not a myth
A Chihuahua and a Great Dane don’t age the same. We use the AKC’s size-based chart, so a giant breed’s years count for more than a toy breed’s.
🩺 Life stage & lifespan
See whether your pet is a puppy, adult, or senior — and their typical lifespan — so you know what care to plan for next.
⚡ Instant & free
No sign-up, no math. Pick a breed (or size), slide the age, and the answer updates as you go.
Calculate by breed
Jump straight to your breed’s age chart and life-expectancy guide.
Helpful guides
Why “1 dog year = 7 human years” is wrong
The classic rule of thumb is charming, but it isn’t how pets actually age. Dogs and cats grow up fast in their first two years — a one-year-old dog is already roughly a 15-year-old human, and reaches about 24 “human years” by age two. After that, aging slows down, and how quickly it slows depends on size: small dogs age gently and often live 13–16 years, while giant breeds age quickly and may reach the same life stage years sooner.
Our calculator follows the American Kennel Club’s size-based chart and standard veterinary life-stage guidance, so the number you get reflects your pet’s real stage of life — not a one-size-fits-all multiplier.
How to use the calculator
- Pick Dog or Cat, then choose your breed — or “Mixed / not sure” and set the size.
- Slide to your pet’s age. The human-year equivalent, life stage, and typical lifespan update instantly.
- Use the life-stage to plan care: seniors often need more frequent check-ups, joint support, and diet changes.
PetYears is for general education only and is not veterinary advice. Every animal is an individual — for anything about your pet’s health, please talk to your veterinarian.