Dog age calculator
How old your dog is in human years — small dogs and big dogs age differently.
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Example
Example: a 7-year-old Labrador is about 50 in human years
A Labrador of about 30 kg (65 lb) turns seven. Choose Large (25–45 kg / 55–100 lb), type 7 years and 0 months, and keep “Show the chart” on.
- In human years a large dog of 7 is about 50: 15 after the first year, 24 after the second, and 50 in the Large column at 7.
- Life stage: Senior, which for large dogs begins at about 6 years.
- The DNA-based estimate is higher, about 62 (16 × ln 7 + 31), from a study of Labradors.
- In the chart the arrow marks the 7 row: a small dog of 7 is about 44, a medium one 47, a giant breed 56.
| Age | Small | Medium | Large | Giant |
|---|---|---|---|---|
| 1 | 15 | 15 | 15 | 12 |
| 2 | 24 | 24 | 24 | 22 |
| 5 | 36 | 36 | 36 | 45 |
| 7 | 44 | 47 | 50 | 56 |
| 10 | 56 | 60 | 66 | 79 |
| 12 | 64 | 69 | 77 | 93 |
| 15 | 76 | 83 | 93 | 114 |
At seven the Labrador is about 50 by the chart and around 62 by the DNA formula — a senior either way. Both are averages; breed, health and care change how each dog ages.
How it works
- Choose the size of your dog and type its age in years and months.
- Read its age in human years, its life stage and the DNA-based estimate.
- Look at the chart for every age from 1 to 20, side by side for the four sizes.
Frequently asked questions
- Is one dog year really seven human years?
- No — that old rule is too simple. A dog’s first year is about 15 human years and the second about 9 more; after that each year counts for about 4 to 8 human years depending on size.
- Why do big dogs age faster?
- Large and giant breeds grow quickly but have shorter lives, so after the first two years each of their years counts for more human years than a small dog’s. That is why the chart has four columns.
- What is the DNA-based estimate?
- A formula from a study of how dogs’ DNA changes with age — human age ≈ 16 × ln(dog age) + 31. It ages young dogs faster than the chart, and it was measured in one breed, so treat it as a second opinion.
- When is a dog a senior?
- Roughly from 7 years for small and medium dogs, 6 for large and 5 for giant breeds. Senior dogs benefit from check-ups twice a year.
- How old is a 1-year-old dog in human years?
- About 15 for a small, medium or large dog and 12 for a giant breed; at 2 years it is 24 (22 for a giant). Months count too: a medium-sized puppy of 6 months is about 8.
- How old is a 10-year-old dog in human years?
- About 56 for a small dog, 60 for a medium one, 66 for a large dog and 79 for a giant breed, by the chart. The DNA-based estimate for 10 years is about 68, whatever the size.
- Is anything sent anywhere?
- No. It is worked out in your browser.
Made for a specific use
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