How old is that in dog years?
The "multiply by seven" rule is wrong. A dog reaches adolescence in a year and then ages far more slowly.
Almost exactly a dog aged 8
45 yr is longer than 4 of the 6 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| dog aged 1 | 14.6 yr | 3.09× | About 15 human years |
| dog aged 2 | 24.1 yr | 1.87× | About 24 human years |
| dog aged 5 | 38 yr | 1.18× | About 37 human years |
| dog aged 8 | 44.4 yr | 1.01× | About 45 human years |
| dog aged 12 | 53.9 yr | 0.835× | About 53 human years |
| dog aged 16 | 58.6 yr | 0.768× | About 59 human years |
Worth knowing
- A better rule than "times seven" is 16 × ln(dog age) + 31, derived in 2020 from DNA methylation in Labradors.
- That formula makes a one-year-old dog about 31 human years old and a twelve-year-old dog about 71 — closer to how vets already treated them.
Frequently asked
Is the seven-year rule true?
No. It gives roughly the right lifespan ratio and the wrong shape. Dogs mature in about a year and then age slowly, so the curve is logarithmic, not linear.
Do bigger dogs age faster?
Yes, markedly. A Great Dane is elderly at seven; a chihuahua may be barely middle-aged at ten. Any single formula averages across that.
How to read this
Equivalences follow the 2020 epigenetic-clock study on Labrador retrievers and are approximate for other breeds.