A 7-year-old medium dog is about 49 in human years, a giant breed about 59. The epigenetic formula gives 62.
General information, not medical advice. Read the disclaimer
- Small (up to 9 kg / 20 lb)
- Medium (10–22 kg / 21–50 lb)
- Large (23–40 kg / 51–90 lb)
- Giant (over 40 kg / 90 lb)
- Epigenetic formula
| Dog age (years) | Small (up to 9 kg / 20 lb) | Medium (10–22 kg / 21–50 lb) | Large (23–40 kg / 51–90 lb) | Giant (over 40 kg / 90 lb) | Epigenetic formula |
|---|---|---|---|---|---|
| 1 | 15 | 15 | 15 | 15 | 31 |
| 2 | 24 | 24 | 24 | 24 | 42 |
| 3 | 28 | 29 | 30 | 31 | 49 |
| 4 | 32 | 34 | 36 | 38 | 53 |
| 5 | 36 | 39 | 42 | 45 | 57 |
| 6 | 40 | 44 | 48 | 52 | 60 |
| 7 | 44 | 49 | 54 | 59 | 62 |
| 8 | 48 | 54 | 60 | 66 | 64 |
| 9 | 52 | 59 | 66 | 73 | 66 |
| 10 | 56 | 64 | 72 | 80 | 68 |
| 11 | 60 | 69 | 78 | 87 | 69 |
| 12 | 64 | 74 | 84 | 94 | 71 |
| 13 | 68 | 79 | 90 | 101 | 72 |
| 14 | 72 | 84 | 96 | 108 | 73 |
| 15 | 76 | 89 | 102 | 115 | 74 |
| 16 | 80 | 94 | 108 | 122 | 75 |
How it is computed
Size columns use the common veterinary rule of thumb: the first year equals 15 human years, the second adds 9, and each later year adds 4 (small), 5 (medium), 6 (large) or 7 (giant). The last column is the epigenetic clock of Wang et al. (2020): human age = 16 × ln(dog age) + 31.
FAQ
Is one dog year really seven human years?+
No. Dogs mature very fast in the first two years, then age more slowly; large breeds age faster than small ones.
Why do the two methods disagree?+
The size rule comes from veterinary experience of when breeds reach old age; the epigenetic formula comes from DNA changes measured in Labrador retrievers. Both are estimates.