Actual dog years

How to Figure Out Your Dog’s Age

If you own a dog, you've heard this rule: 1 year for Fido equals 7 years for you. Turns out, the math isn't that simple. Dogs mature more quickly than we do early on. So the first year of your fuzzy friend’s life is equal to about 15 human years.

Table of Contents Show

How to Figure Out Your Dog’s Age
Clues to Look For
The Easy Calculation of Dog’s Age
The More Accurate Calculation of Dog Years
Dog Age Calculator: Dog Years to Human Years
Dog Years to Human Years Chart
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Size and breed also play a role. Smaller dogs tend to live longer than larger ones, but they may mature more quickly in the first few years of life. A huge pup might age more slowly at first, but be nearing middle age at 5. Tiny and toy breeds don't become "seniors" until around age 10. Medium-sized pooches are somewhere in the middle on both counts.

Clues to Look For

If you’ve adopted a puppy or dog but don't know their history, you may not know how old they are. Even if you don’t know the birth date, you can still guess their age.

Their teeth should give you a rough idea of their age. These guidelines will vary from dog to dog, and they also depend on the kind of dental care (if any) they had before you got them.

By 8 weeks: All baby teeth are in.
By 7 months: All permanent teeth are in and are white and clean.
By 1-2 years: Teeth are duller and the back teeth may have some yellowing.
By 3-5 years: All teeth may have tartar buildup and some tooth wear.
By 5-10 years: Teeth show more wear and signs of disease.
By 10-15 years: Teeth are worn, and heavy tartar buildup is likely. Some teeth may be missing.

Your vet can also guess their age based on a complete physical exam or tests that look at bones, joints, muscles, and internal organs. Senior dogs might show some specific signs of aging.

Cloudy eyes
Gray hair. It starts around the muzzle then spreads to other areas of the face, head, and body.
Loose skin
Stiff legs

Body

How old is your dog in human years? We used to simply multiply a dog’s age by seven. However, this calculation isn’t so cut-and-dried. See our dog age calculator and chart to discover your dog’s age.

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.

For example, a dog which is 5 years old is 35 “human years.” This isn’t a bad way to go from a health perspective because it helps us humans realize that our dogs aren’t the same as children.

As pets get older, they need extra care and attention. Small dogs are generally considered “senior” at seven years of age. Larger breeds are often senior when they are 5 to 6 years of age.

Be aware of arthritis and related discomfort or irritability, weight control, sight and hearing issues, and any changes in behavior or activity which could indicate more serious issues.

Visit your vet for exams regularly; adjustments can be made to give your pets a more comfortable, longer, healthier life.

The More Accurate Calculation of Dog Years

Statistics from pet-insurance companies, breed-club surveys, and veterinary hospitals have helped us learn more about how dogs age.

Contrary to common belief, dogs do not age at a rate of 7 human years for each year in dog years.

According to the American Veterinary Medical Association:

The first year of a medium-sized dog’s life is equal to approximately 15 years of a human’s life.
The second year of a dog’s life equals about nine years for a human.
And after that, every human year equals approximately four or five years for a dog.

In other words, the number of human years piles onto a dog’s life more quickly during the dog’s rapid growth to maturity.

Dog Age Calculator: Dog Years to Human Years

If we think like a dog, here’s how a dog’s age compares to a human’s age! Note that this calculator is for a medium size breed of dog. Consult the chart below to see the differences between different size dogs (small, medium, large, giant). It should give you a good sense of where your dog is in the development/aging process.

Dog Years to Human Years Chart

Age of Dog (dog’s age according to the calendar)	Dog’s Age in Human Years (dog’s age in equivalent human years, based on stage of breed size)
Small	Medium	Large	Giant
1 year	15	15	15	12
2 years	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

Source: AKC, “How to Calculate Dog Years to Human Years”

Have a cat? See our Cat Age Chart!

Is your dog starting to enter its elderly years? Get some tips for caring for an old pup.

Also, check our home remedies for your pet’s arthritis.

Is 1 year really 7 years for a dog?

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.