Dog Age Calculator

Enter your dog's age and choose its adult size. The first dog year counts as about 15 human years and the second adds about 9, so 2 years is about 24. After that each dog year adds about 4 (small), 5 (medium), 6 (large) or 7 (giant) human years. For example, a 5-year-old medium dog is 15 + 9 + 5 × 3 = 39.

No. The times 7 rule is an easy shortcut, but it is not accurate. A 1-year-old dog is closer to a teenager of about 15, and dogs age more slowly after their first two years. By the old rule a 5-year-old dog is 35, but the size chart gives 36 to 45 depending on the dog's size.

About 15 human years, for dogs of every size. A dog of 2 years is about 24. A puppy of 6 months is about 7.5 human years.

If you mean a 5-year-old dog in human years, a small dog is about 36, a medium dog 39, a large dog 42 and a giant dog 45. A 10-year-old dog is about 56 (small), 64 (medium), 72 (large) or 80 (giant). The Dog Age Chart by Size lists 1 to 18 years.

Open the Human to Dog Years tab, enter the person's age and pick a size. It works the chart backwards. For a medium dog, a 30-year-old person is like a dog of 3 years 2 months, and a 40-year-old person is like a dog of 5 years 2 months.

Large dogs tend to age faster than small dogs, and small dogs tend to live longer. So after the first two years a giant dog adds about 7 human years for each dog year and a small dog only about 4. The first two years are the same for every size.

Use the weight your dog will have as a full-grown adult. Under 20 lb is small, 20 to 50 lb is medium, 50 to 90 lb is large and over 90 lb is giant. A Chihuahua is small, a Beagle is medium, a Labrador is large and a Great Dane is giant.

Choose the size the dog is expected to reach as an adult, which is usually clear from its parents or from your vet. If you are not sure, medium is a reasonable middle choice, and you can compare all four sizes in the answer.

A puppy of 1 month is about 1.3 human years, 3 months about 3.8, 6 months about 7.5, 12 months 15 and 18 months about 19.5. The Puppy Age in Months table lists 1 to 24 months.

If you know the birthday, use the From Birthday tab. If you do not, your vet can give a rough estimate from things like the teeth and the general condition of the dog, but it is only an estimate, and a rescue may also have a best guess.

In 2020 researchers at the University of California San Diego studied DNA changes in 104 Labrador Retrievers and suggested human age ≈ 16 × ln(dog age) + 31. It gives about 42 at 2 years and about 57 at 5 years. It comes from one breed, so this calculator uses the size chart for the answer and shows the research only for comparison.

Researchers have noticed that, unlike in most animal species, larger dogs tend to have shorter lives than smaller ones, but the reasons are still being studied. That is why the chart adds fewer human years per dog year for small dogs.

It depends on the size: larger dogs reach their senior years sooner than small dogs. Your vet can tell you when your own dog counts as senior and what care it needs, so this page does not give a fixed age.

It gives an estimate from a general chart, not a measurement. Breed, health, diet and lifestyle all change how a dog ages, so two dogs of the same age and size can be quite different. Use it for interest and ask your vet about your own dog.

A 15-year-old dog is about 76 (small), 89 (medium), 102 (large) or 115 (giant) in human years, and a 16-year-old is about 80, 94, 108 or 122. Very old dogs vary a lot, so ask your vet about care.

No. The calculation happens in your browser, and what you enter is not stored or sent to any server. A link you copy keeps the numbers after the # sign, which browsers never send to a server.