# How do you calculate a dog's age in 'dog years'?

== == == == A dog's lifespan is only a fraction of the average human's lifespan, which means that a dog ages more quickly in the same amount of time. A human of six is very young, but a dog of six is already middle aged. How can we translate a dog's chronological (actual) age into something we can compare with a human's development, maturity, and aging process? How do we know when a dog is a teenager, an adult, a senior citizen? 'Dog years' are a representation of of how old a dog would be if he lived as long as a human. On average, dogs age seven times as quickly as humans. One way to estimate how old a dog is in dog years is simply to multiply his chronological age by seven. This is probably the most popular technique for estimating a dog's physical age compared to his actual age. Unfortunately, it's not very accurate because dogs mature much more quickly than humans do. Dogs have shorter childhoods and longer adulthoods. Dogs start walking at three weeks and reach physical maturity at 18 months. If we use the seven-for-one rule that would be the same as a human toddler walking at five months or a human child reaching physical maturity by age 11. Also, while a 15-year-old dog would be considered the equivalent of a 105-year-old person, many more dogs live to be 15 than humans live to be 105. A more accurate formula would be: 10 and 1/2 dog years for the first two years, then four dog years per year thereafter. However, this formula does not take the dog's size into consideration. We know that small dogs tend to live longer than large dogs, as much as twice as long. One way to handle the influence of size on a dog's aging is to change the multiplication factor used once a dog is past two years old. for small to medium sized dogs, multiply by four

for large dogs, multiply by six

for giant breeds, multiply by eight Using this adjustment for size we can estimate that a 65 year old human is approximately equivalent to a 12-year-old small dog, a nine-year-old old large dog or a six-year-old giant dog. It still isn't perfect, but it is more accurate than assuming dogs age the same regardless of size. We know it is rare for a large dog to make it past 12 and extremely rare for a giant dog to do so. If all of this math is too much to face, fear not! There are several handly dog age calculators available on the Internet (see the links below). Try several and see how they compare. They may give slightly different ages in dog years depending on which formula they use for calculations. ---- The old rule of thumb that dogs age seven times as fast as humans comes from dividing the average human life span by the average canine life span. But it's not very accurate. As Snopes points out, most dogs reach adulthood in roughly 18 months, which would be the equivalent of a 10-year-old child. Also, while a 15-year-old dog would be considered the equivalent of a 105-year-old person, many more dogs live to be 15 than humans live to be 105. The handy Online Conversion site suggests that a more accurate formula would be: 10 and 1/2 dog years for the first two years, then four dog years per year. Maxie Beagle offers a scaled chart that distinguishes between small and large dogs (smaller breeds tend to live longer). DogAge measures your dog's biological age in human years according to factors such as breed, weight, lifestyle, and behavior. You'll find another handy lifespan chart at (where else?) DogYears.com

See related links below for more information. ---- The old rule-of-thumb that one dog year equals seven years of a human life is not accurate. The ratio is higher with youth and decreases a bit as the dog ages. Depending on breed, a dog experiences the raging hormones of adolescence anywhere from eight months to two years or more. Generally, a dog of six years has aged about as much as a 45-year-old human. At 10, she's like a human of 65; at 12, a human of 75; and at 15, a human of 90. For Example: for a dog that is 10 yrs. old

(the first two years) 10.5 * 2 = 21

(plus the next eight years) 4 * 8 = 32

21 + 32 = 53 years old A dog's lifespan is only a fraction of the average human's lifespan, which means that a dog ages more quickly in the same amount of time. ----

2 = 24

3 = 28

4 = 32

5 = 36

6 = 40

7 = 44

8 = 48

9 = 52

10 = 56

11 = 60

12 = 64

13 = 68

14 = 72

15 = 76

16 = 80