The Easy Calculation of Dog's Age The easy way to calculate a dog's age is to take 1 dog year and multiple it by 7 years. This is based on an assumption that dogs live to about 10 and humans live to about 70, on average.
According to the well-known ''rule of paw,'' one dog year is the equivalent of 7 years. Now scientists say it's wrong. Dogs are much older than we think, and researchers devised a more accurate formula to calculate a dog's age based on the chemical changes in the DNA as organisms grow old.
Age and Dog Size
Dog Age in Human Years | ||
---|---|---|
Size of Dog | Small (<20 lbs.) | Giant (>91 lbs.) |
Age of Dog | Age in Human Years | Age in Human Years |
1 | 18 | 14 |
2 | 24 | 19 |
Medium size dogs: Up to 50 lbs.
Dog Age | Human Age |
---|---|
7 | 47 |
8 | 51 |
9 | 56 |
10 | 60 |
A common rule of thumb for dog owners is that one year for dogs is equivalent to seven human years. But new research shows that young puppies age much faster than young humans do, so that simple one-to-seven year ratio is wrong. A 1-year-old dog is more "like a 30-year-old human," one scientist said.
How do you calculate how old a dog is?
Age of Dog | Human Equivalent | Indicator(s) |
---|---|---|
7 months | 8-10 years | All permanent teeth have grown |
1-2 years | 15-24 years | Teeth starting to yellow and duller |
3-5 years | 28-36 years | Tooth wear and plaque build-up is common |
5-10 years | 36-66 years | Teeth and gums show some signs of disease |
Age and Dog Size
Dog Age in Human Years | ||
---|---|---|
Size of Dog | Small (<20 lbs.) | Large (51-90 lbs.) |
Age of Dog | Age in Human Years | Age in Human Years |
1 | 18 | 15 |
2 | 24 | 20 |
Dog's age | Small breed (up to 9 kg) | Medium breed (9 to 22 kg) |
---|---|---|
18 | 88 | 96 |
19 | 92 | 101 |
20 | 96 | 105 |
21 | 100 | 110 |
Dog years chart
Age of Dog | Small breed | Large breed |
---|---|---|
4 Years | 32 Human Years | 32 Human Years |
5 Years | 36 Human Years | 36 Human Years |
6 Years | 40 Human Years | 45 Human Years |
7 Years | 44 Human Years | 50 Human Years |
About Dog Years Calculator
Age of dog (years) | Age in human years for small breed (<21 lbs) | Age in human years for medium breed (21-50 lbs) |
---|---|---|
6 | 40 | 42 |
7 | 44 | 47 |
8 | 48 | 51 |
9 | 52 | 56 |
Medium size dogs: Up to 50 lbs.
Dog Age | Human Age |
---|---|
1 | 15 |
2 | 24 |
3 | 29 |
4 | 34 |
Dog years chart
Age of Dog | Small breed | Large breed |
---|---|---|
2 Years | 24 Human Years | 24 Human Years |
3 Years | 28 Human Years | 28 Human Years |
4 Years | 32 Human Years | 32 Human Years |
5 Years | 36 Human Years | 36 Human Years |
The second year of a dog equates to approximately nine human years - which makes a 2 year old dog equal to a 24 year old human (15+9=24). After that every human year equals approximately five dog years.