Dog Age Calculator: Your Dog's Age in Human Years
Enter your dog's age and size to see a rough estimate of their age in human years, plus a training tip that fits their stage of life. Nothing you type leaves your browser.
Your dog
This is a rough, general estimate for fun and for planning training. It is not a health assessment. For mixed breeds, use the size your dog is (or will be) as an adult.
How the calculator works
The main number comes from the size based dog age chart below. It follows the same starting points the American Veterinary Medical Association describes: about 15 human years for a dog's first year and about 9 more for the second. After that, each year adds roughly 4 to 8 human years depending on adult size. Between birthdays, the calculator blends the two nearest values.
For dogs one year or older, it also shows a second estimate from a DNA based formula: human age = 16 x ln(dog age) + 31, from a 2020 study of Labrador retrievers by Wang and colleagues. The two methods often disagree, which is a good reminder that any conversion is approximate.
Dog years to human years chart
| Dog age | Small | Medium | Large | Giant |
|---|---|---|---|---|
| 1 | 15 | 15 | 15 | 12 |
| 2 | 24 | 24 | 24 | 22 |
| 3 | 28 | 28 | 28 | 31 |
| 4 | 32 | 32 | 32 | 38 |
| 5 | 36 | 36 | 36 | 45 |
| 6 | 40 | 42 | 45 | 49 |
| 7 | 44 | 47 | 50 | 56 |
| 8 | 48 | 51 | 55 | 64 |
| 9 | 52 | 56 | 61 | 71 |
| 10 | 56 | 60 | 66 | 79 |
| 11 | 60 | 65 | 72 | 86 |
| 12 | 64 | 69 | 77 | 93 |
| 13 | 68 | 74 | 82 | 100 |
| 14 | 72 | 78 | 88 | 107 |
| 15 | 76 | 83 | 93 | 114 |
| 16 | 80 | 87 | 99 | 121 |
Small: up to 20 lb. Medium: 21 to 50 lb. Large: 51 to 100 lb. Giant: over 100 lb. Values are approximate and vary between sources.
What your dog's age means for training
- Young puppies: keep sessions to a few minutes, several times a day, and build a steady routine. Our puppy schedule maker lays out a day for you.
- Adolescents (roughly 6 to 18 months): skills that seemed solid can wobble. Stay patient, keep practicing in new places and see our guide to puppy biting.
- Adults: a great time to add new skills, like loose leash walking, and to use brain games to burn extra energy.
- Older dogs: short, gentle sessions and sniffing games keep their minds busy. Ask your vet before changing exercise.
Dog age questions
Is one dog year really seven human years?
No. The seven year rule is a simple myth. Dogs grow up much faster than people in the first two years: a one year old dog is roughly like a teenager, and a two year old is roughly like a young adult in their twenties. After that, each dog year counts for about four to seven human years, depending on size.
Why does size matter?
Larger and giant breeds tend to have shorter average lifespans than small breeds, so in the later years they age faster in human terms. That is why the chart splits dogs into small, medium, large and giant.
What is the DNA based formula?
A 2020 study by Wang and colleagues in the journal Cell Systems compared age related DNA changes in Labrador retrievers and people and proposed human age = 16 x ln(dog age) + 31. It was built on one breed, so treat it as an interesting second estimate, not a precise answer.
How accurate is a dog age calculator?
Any dog to human age conversion is a rough estimate. Genetics, breed, weight and lifestyle all play a part, and no formula can tell you how a particular dog is aging. Your veterinarian is the right person to talk to about your dog's health at any age.
Can older dogs still learn new things?
Yes. Older dogs can learn new cues and enjoy short, gentle training sessions and scent games. Keep sessions short, use soft treats and ask your vet before adding new physical activity.