How old is your dog in human years? Forget “multiply by seven” — dogs mature fast early on, then age at a pace that depends on their size. Pop in your dog’s age and size for a much more realistic number.
🐕 How dog years really work
The popular “1 dog year = 7 human years” rule is a myth. In reality:
- A dog’s first year ≈ about 15 human years.
- The second year adds about 9 more — so a 2-year-old dog is roughly 24.
- After that, each year adds about 4–7 human years, depending on size.
Why size matters
Smaller dogs live longer and age more slowly in later life; large and giant breeds mature into “seniors” sooner. That’s why this calculator factors in your dog’s adult size.
📊 Quick reference
| Dog age | Small | Medium | Large | Giant |
|---|---|---|---|---|
| 1 yr | 15 | 15 | 15 | 15 |
| 2 yr | 24 | 24 | 24 | 24 |
| 5 yr | 36 | 39 | 42 | 45 |
| 8 yr | 48 | 54 | 60 | 66 |
| 12 yr | 64 | 74 | 84 | 94 |
Based on the widely used size-adjusted method (AKC). For fun, scientists have also proposed an “epigenetic” formula (16 × ln(dog age) + 31) based on DNA — but the size-based table above is the easiest realistic guide. Sources: AKC.
🩺 What your dog’s “real age” means for care
Knowing the human-age equivalent helps you adjust care: senior dogs benefit from more frequent vet check-ups, joint support, softer exercise and cozier rest. Find a vet on the Marin vet clinics map, and match activity to life stage with the dog exercise calculator.
Whether you’ve got a bouncy puppy or a gentle senior, Andy tailors walks and in-home sitting to your dog’s pace. Book in a couple of taps.
Book a walk or sitting 🐾