The old rule that one dog year equals seven human years is a myth. Dogs grow up very fast in their first two years, and after that, large and giant breeds age faster than small dogs. This calculator uses the dog-to-human age chart published by the American Veterinary Medical Association (AVMA).
How the calculation works
- A one-year-old small, medium or large dog is about 15 in human years; a giant breed is about 12.
- At two, most dogs are about 24 in human years.
- After that, each year adds about 4 human years for small dogs and more for bigger dogs, up to about 7 for giant breeds.
Dog age chart
| Dog age | Small (20 lb or less) | Medium (21–50 lb) | Large (51–100 lb) | Giant (over 100 lb) |
|---|---|---|---|---|
| 1 | 15 | 15 | 15 | 12 |
| 2 | 24 | 24 | 24 | 22 |
| 4 | 32 | 32 | 32 | 38 |
| 6 | 40 | 42 | 45 | 49 |
| 8 | 48 | 51 | 55 | 64 |
| 10 | 56 | 60 | 66 | 79 |
| 12 | 64 | 69 | 77 | 93 |
| 14 | 72 | 78 | 88 | 107 |
| 16 | 80 | 87 | 99 | 121 |
When is a dog a senior?
Bigger dogs reach their senior years sooner. Many large and giant breeds are considered seniors at around 6 to 7 years, while many small dogs reach that stage later. Your veterinarian can tell you when your own dog should start senior check-ups.
Comfort for older dogs
Older dogs often appreciate a soft, supportive place to rest and easy-to-reach food and water. See our gear for senior dogs and cozy dog beds. This calculator is an estimate, not medical advice; every dog ages a little differently.