Dog Age Calculator
Convert your dog's age to human years based on breed size. Uses the latest veterinary science.
Dog Age Calculator
Dog years to human years
Fully mature, prime of life
How to Use Dog Age Calculator
- 1 Enter your dog's age in years and months
- 2 Select your dog's size category (small, medium, large, or giant)
- 3 See the equivalent human age and your dog's life stage
- 4 Check the aging timeline to understand your dog's development
- 5 Copy the result to share with your vet
What You Get
Accurate dog-to-human age conversion using AVMA-approved rates. Accounts for the accelerated aging in the first two years and size-dependent rates afterward. Shows life stage (puppy through geriatric) and a visual aging timeline.
Input: 1 year old, Medium dog
Output: 15 human years (Junior)
Input: 3 years old, Small dog
Output: 28 human years (Adult)
Input: 7 years old, Large dog
Output: 54 human years (Mature)
Input: 10 years old, Giant dog
Output: 80 human years (Geriatric)
How old is my dog in human years?
Use our calculator to find out. A 1-year-old dog equals about 15 human years, a 2-year-old equals 24 human years, and after that it depends on the dog's size. Small dogs age slower than large breeds.
Is 1 dog year really 7 human years?
No, the "multiply by 7" rule is outdated and inaccurate. Dogs age much faster in their first two years (15 + 9 = 24 human years), then the rate slows down and varies by size. A 1-year-old dog is developmentally closer to a 15-year-old human, not 7.
Why do small dogs live longer than large dogs?
Larger dogs age faster after maturity. A Great Dane may be senior at age 6, while a Chihuahua is still in its prime. Scientists believe this is because larger dogs grow faster, which accelerates cellular aging. Small dogs (under 20 lbs) can live 14-16 years, while giant breeds often live only 7-10 years.
At what age is a dog considered senior?
It depends on size. Small dogs become seniors around 10-12 years (65+ human years), medium dogs around 8-10, large dogs around 6-8, and giant breeds as early as 5-6 years. Your vet may recommend senior wellness exams starting at these ages.
How do you calculate a dog's age accurately?
The American Veterinary Medical Association uses this guideline: Year 1 = 15 human years, Year 2 = 9 more human years (total 24), then each additional year equals 4-7 human years depending on size. Small dogs add 4 years, medium 5, large 6, and giant 7 per year after age 2.
How old is a 5 year old dog in human years?
A 5-year-old dog's human age depends on size: Small (under 20 lbs) = 36 human years, Medium (21-50 lbs) = 39 years, Large (51-100 lbs) = 42 years, Giant (100+ lbs) = 45 years. All sizes are 24 at age 2, then the rate differs.
What is the oldest dog ever recorded?
The oldest verified dog is Bluey, an Australian Cattle Dog, who lived to 29 years and 5 months (1910–1939). A Portuguese dog named Bobi was briefly listed at 31 years, but Guinness revoked the record in 2024. These are extreme outliers — most dogs live 10-15 years.
Is dog age data stored on any server?
No. All calculations happen locally in your browser. Your dog's age and breed information are never sent to any server. The tool is 100% private and free.
All calculations happen locally in your browser. No data is sent to any server.