Dog years to human years chart
| Dog age | Small (≤20 lb) | Medium (21 to 50 lb) | Large (51 to 100 lb) | Giant (100+ lb) |
|---|---|---|---|---|
| 1 year | 15 | 15 | 15 | 12 |
| 2 years | 24 | 24 | 24 | 22 |
| 3 years | 28 | 28 | 28 | 31 |
| 4 years | 32 | 32 | 32 | 38 |
| 5 years | 36 | 36 | 36 | 45 |
| 6 years | 40 | 42 | 45 | 49 |
| 7 years | 44 | 47 | 50 | 56 |
| 8 years | 48 | 51 | 55 | 64 |
| 9 years | 52 | 56 | 61 | 71 |
| 10 years | 56 | 60 | 66 | 79 |
| 11 years | 60 | 65 | 72 | 86 |
| 12 years | 64 | 69 | 77 | 93 |
| 13 years | 68 | 74 | 82 | 100 |
| 14 years | 72 | 78 | 88 | 107 |
| 15 years | 76 | 83 | 93 | 114 |
| 16 years | 80 | 87 | 99 | 121 |
The table follows the size-based chart shared by the American Veterinary Medical Association. Want it on one printable page? See the dog age chart.
Why the "multiply by 7" rule is wrong
The seven-year rule probably came from a simple comparison of average lifespans: people living about 70 years and dogs about 10. But a one-year-old dog can have puppies and is nearly full-grown, which no 7-year-old child can do. Real dog aging is front-loaded. The first two years cover the human equivalent of childhood and adolescence. After that, every dog year counts for 4 to 7 human years, depending on size.
When is a dog a senior?
Size matters a lot. As a rough guide, small dogs become seniors around 10 to 12, medium dogs around 8 to 10, large dogs around 8, and giant breeds as early as 5 or 6. Senior dogs should see the vet every six months. Blood and urine tests catch kidney disease, diabetes and thyroid problems early, when they're much easier to manage.
Look up a specific age
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Frequently asked questions
Is one dog year really seven human years?
No. That rule is a myth. Dogs mature much faster early on: a one-year-old dog is roughly like a 15-year-old teenager, and a two-year-old like a 24-year-old. After that, aging slows to about 4 to 7 human years per dog year, depending on size.
Why do big dogs age faster?
Large and giant breeds have shorter lifespans and reach "senior" status sooner. A Great Dane is considered senior at about 6, while a Chihuahua may not be senior until 10 or later. Scientists are still working out why, but faster growth seems to play a part.
How do I calculate my dog’s age in human years?
Count the first year as 15 human years and the second as 9 more (24 total). After that, add about 4 years per dog year for small dogs, 5 for medium, 6 for large and 7 or more for giant breeds. The calculator does this for you using the AVMA size chart.
What is the new formula for dog years?
A 2020 University of California San Diego study comparing DNA methylation in Labradors and people proposed: human age = 16 × ln(dog age) + 31. It suggests puppies age extremely fast, so a 1-year-old Lab is like a 31-year-old. It was built on one breed, so most vets still use size-based charts.