How it works
The first year counts as 15 human years and the second adds 9; after that each year adds about 5 for dogs and 4 for cats. The stage badge follows the same curve: young under one year, senior from about 7 for dogs and 10 for cats.
36 months dog → about 29 human years · Adult
Tips
- Large dog breeds age faster than small ones — treat the number as a guide.
- Senior pets deserve twice-yearly vet checks even when they seem fine.
- Everything runs in your browser; nothing is uploaded.
Standards and sources
- AVMA — Caring for senior cats and dogs
- AAHA — My Pet's Physiological Age (dog & cat age chart)
- AAHA/AAFP — 2021 Feline Life Stage Guidelines
Last reviewed October 13, 2026
Frequently asked questions
Is ×7 accurate?
No — that myth overstates young pets and understates old ones. This tool uses the veterinary curve: fast early years, then about 5 per year for dogs and 4 for cats.
When is a dog senior?
Around 7 years (84 months) for most dogs; cats around 10 years. Large breeds age faster than small ones.
Why enter months, not years?
The first two years change so fast that months give a much fairer number.