Two Beagles, two columns
The Beagle is unusual in that the AKC standard describes two sizes: dogs 13 inches and under at the shoulder, weighing under 20 pounds, and dogs from 13 to 15 inches weighing 20 to 30 pounds. On the size chart that is the dividing line between the small column (20 lb or less) and the medium one (21 to 50 lb). This page opens on medium; if your Beagle is the smaller variety, or simply stays under 20 lb as an adult, choose Small.
Until age 5 it makes no difference: both columns read 15 at one year, 24 at two and 36 at five. From 6 the medium column pulls ahead a little more each year: at 6 the two differ by 2 human years, at 10 by 4 (60 against 56), and at 15 by 7 (83 against 76).
A wide senior window
The AKC gives Beagles a life expectancy of 10 to 15 years, a wider range than the two years it gives Labradors (11 to 13). Using the last quarter of the life span as the senior stage, this page marks it from about 7.5 to 11.3 years. In practice that means watching for age-related changes from around 7 or 8 and asking your vet how often your Beagle should be seen as it gets older.
The DNA formula shown next to the chart, 16 × ln(age) + 31, doesn’t use size at all, so it gives the same answer for both Beagle varieties.
Beagle: dog years to human years
| Beagle's age | Size chart | DNA formula | Life stage |
|---|---|---|---|
| 1 year | 15 | 31 | Young adult |
| 2 years | 24 | 42 | Young adult |
| 3 years | 28 | 49 | Young to mature adult |
| 4 years | 32 | 53 | Mature adult |
| 5 years | 36 | 57 | Mature adult |
| 6 years | 42 | 60 | Mature adult |
| 7 years | 47 | 62 | Mature adult |
| 8 years | 51 | 64 | Entering the senior years |
| 9 years | 56 | 66 | Entering the senior years |
| 10 years | 60 | 68 | Entering the senior years |
| 11 years | 65 | 69 | Entering the senior years |
| 12 years | 69 | 71 | Senior |
| 13 years | 74 | 72 | Senior |
| 14 years | 78 | 73 | Senior |
| 15 years | 83 | 74 | Senior |
| 16 years | 87 | 75 | Senior |