How dog years are calculated
The old "multiply by 7" rule is too simple. Dogs mature fast early and age slower later, and big dogs age faster than small ones. The vet-recommended method:
- First year = 15 human years
- Second year = +9 (total 24)
- Each year after = +4 (small), +5 (medium), +6 (large) or +7 (giant)
A 2019 study of DNA methylation proposed human age = 16 × ln(dog age) + 31 — that gives 31 for a 1-year-old and 62 for a 7-year-old Labrador. Both estimates are shown above.
Life stages
| Dog age | Stage |
|---|---|
| 0–1 | Puppy |
| 1–3 | Young adult |
| 3–7 | Adult |
| 7–10 | Mature |
| 10+ | Senior (large breeds from 7–8) |