How to Calculate Your Dog's Age (2024)

If you own a dog, you've heard this rule: One year for Fido equals 7 years for you. Turns out, the math isn't that simple. Researchers now have a more accurate way of calculating a dog's age that takes into account theirsize, breed, and changes to their DNA over time.

Dog Years to Human Years

How do dog years work? 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.

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-size pooches are somewhere in the middle on both counts.

Dog Age Chart

How to Calculate Your Dog's Age (1)

How Do Dogs Age?

Scientists are still trying to figure out why smaller dogs age more slowly and live longer than bigger dogs. One theory is that it's related to age-related health issues in dogs. Many of these tend to impact larger dogs earlier. Since larger dogs age faster, this also speeds up abnormal cell growth, which causes conditions like cancer.

How Long Do Dogs Live?

Many things can affect how long your dog lives, including their size, breed, genes, and lifestyle:

  • Size and breed. Smaller dog breeds tend to outlive larger ones. On average, you can expect a small dog breed such as chihuahua, Chinese crested, and Pomeranian to be with you for around 10 to 15 years, with some breeds living to 18 years old. Meanwhile,large dog breeds like German shepherds, golden retrievers, and Labrador retrievers usually live between 8 and 12 years.
  • Genetics. Their genes contribute to your dog’s lifespan. Like you, dogs inherit genes from their parents that may raise their chances of certain health conditions. That’s why it’s important to choose a breeder whouses responsible breeding practices.
  • Lifestyle. Serious injuries, infectious diseases, and extra pounds can shorten dog life expectancy.

Other things have also led to dogs living longer, better lives, including advances in nutrition, medicine, and the diagnosis and treatment of disease.

Signs of Aging in Dogs

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.

Dog 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 they're 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 your dog's 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, including:

  • Cloudy eyes
  • Gray hair. It starts around the muzzle and then spreads to other areas of the face, head, and body.
  • Loose skin
  • Stiff legs
  • Bad breath
  • Trouble getting around
  • New lumps
  • Weight changes
  • Trouble peeing or pooping, or loss of bowel and bladder control
  • Fear of people or objects that they once recognized
  • Sleep changes (uneasiness or pacing at night)
  • More barking
  • Doing the same thing over and over
  • Forgetfulness (cues and commands)
  • Peeing and pooping where they shouldn't
  • Anxiousness
  • Confusion
  • Becoming less active

Why Does My Dog’s Age Matter?

When you know how old your dog is, you cantake better care of them for their entire life. Watch out for physical and mental signs of aging in your small dog around age 7 or 8, and in your large dog around 5 or 6 years old.

How to Help Your Dog Live Longer

Here are some tips to help your dog live aa longer and healthier life:

  • Feed them healthy food. Use a high-quality pet food with protein, fats, carbohydrates, vitamins, and minerals. Look for the AAFCO (Association of American Feed Control Officials) label on your pet food, which means it's complete and balanced nutrition.
  • Keep their weight in a normal range. Talk to your vet about what a normal weight is for your dog and how much exercise they should get. But in general, high-energy breeds need more exercise than low-energy ones.
  • Keep their vaccines and preventives current. The most important are parvovirus, heartworm prevention, flea and tick control, intestinal parasite control, distemper, rabies, and adenovirus.
  • Be aware of the symptoms of diseases linked to your breed of dog. Ask your vet which signs to look out for in your specific breed.
  • Take them to the vet. Your dog should have a checkup and bloodwork done on a regular schedule. This can vary based on their age and individual needs.
  • Keep them away from toxins and other harmful stuff. This includes edible and inedible things like alcohol, caffeine, chocolate, antifreeze, fabric softener sheets, insecticides, and pesticides.

Takeaways

Scientific research has given us new insight into how dogs age. We now know that smaller dog breeds tend to age more slowly than larger ones. But lifestyle changes like healthier food and watching your dog’s weight can help all dogs, no matter their size, live the longest possible life. Figuring out your own pet's age can help you take the best care of them through the years.

Dog Age FAQ

How old is 7 years in dog years?

It depends on the dog's size, but a medium-size 7-year-old dog is about 47 in human years.

How old is a 10-year-old dog?

A medium-sized 10-year-old dog is about 60 in human years.

What is the dog age equivalent calculator?

In 2019, researchers at the University of California San Diego came up with a new way to figure out a dog's age in human terms. They used a concept called DNA methylation, which changes in both humans and dogs as they get older.

Researchers studied around 100 Labrador retrievers of different ages. They discovered a formula to convert a dog's age to human years by taking the natural logarithm of the dog's age, multiplying it by 16, and adding 31. While the formula isn't perfect for all dog breeds because they age differently, it's still more accurate than multiplying a dog's age by seven.

How to Calculate Your Dog's Age (2024)

FAQs

How to Calculate Your Dog's Age? ›

A dog's age (in years) x 7 = Age in “dog years.” For example, if your dog was born 7 years ago, he is 49 years old in “dog years.” (Or, stated differently, a 7-year old dog is at a similar stage in aging to a 49-year old human.)

How old is 7 years in dog years? ›

A dog's age (in years) x 7 = Age in “dog years.” For example, if your dog was born 7 years ago, he is 49 years old in “dog years.” (Or, stated differently, a 7-year old dog is at a similar stage in aging to a 49-year old human.)

How old is 12 years in dog years? ›

Medium size dogs: Up to 50 lbs.
Dog AgeHuman Age
1165
1269
1374
1478
14 more rows

How old is 20 in dog years? ›

Dog's ageSmall breed (up to 9 kg)Large breed (22 to 44 kg)
1992115
2096121
21100126
22104132
21 more rows

At what age is your dog old? ›

This is a general guide: Small breeds are considered senior dogs when they turn 10 to 12 years old. Medium breeds are considered senior dogs when they hit 8 to 9 years old. Large and giant breeds are considered senior dogs at around 6 to 7 years old.

How old is a 5 year old dog? ›

36 Years Old

How old is a 10-year-old dog? ›

Dog Age Calculator: Dog Years to Human Years
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 average breed size)
SmallMedium
95256
105660
116065
13 more rows
Apr 5, 2024

Is 12 considered old for a dog? ›

By the age of 12 years old, dogs of all sizes are considered senior or geriatric. Senior and geriatric dogs have different nutritional needs to puppies and adult dogs and will need a diet that meets those needs.

How old is 31 in dog years? ›

Using that equation: a 1-year-old dog is like a 31-year-old human; a 3-year-old dog is like a 49-year-old human; a 7-year-old dog is like a 62-year-old human.

Is 14 old for a dog? ›

Is 14 years old for a dog? 14 years old can generally be considered old for a dog. A small dog is considered old when they're 11, a medium dog is considered old when they're 10, and a large dog is considered old when they're 8.

What is the oldest dog alive today? ›

On 7 December 2022, in the U.S. state of Ohio, a 23-year-old chihuahua named Spike was certified as the oldest living dog; however, that title was short-lived as Bobi's age was verified two weeks later. Spike regained his title as the world's oldest living dog after Bobi's death.

How old is 30 in dog age? ›

So, a three year old dog is in their late twenties, a four year old dog is in their early thirties, and a five year old dog is in their mid to late thirties.

What is 15 in dog years? ›

Dog age calculator
Size of DogSmallGiant
1368100
1472107
1576114
1680121
13 more rows

At what age do dogs start slowing down? ›

As they age, however, they will begin to take longer and more frequent breaks between spurts. Most dogs will lose that seemingly abundant energy as they pass the three-to-four-year mark. As dogs get even older, their bodies will begin to betray them.

How do I know if my senior dog is suffering? ›

The signs include excessive grooming, eye changes, weight loss, twitching or tight muscles, heavy panting, and extreme restlessness. Others are aggression, whining and whimpering, excessive vocalization, and difficulty walking and getting up the stairs.

Do dogs slow down as they age? ›

It's normal for your dog to slow down a little as they age. They will typically have less stamina, and won't be able to exercise for as long as they did when they were younger. You may need to reduce the length of walks and adapt to less strenuous activities – they may need to 'retire' as your jogging partner!

How is 1 year 7 years in dog years? ›

The 1 human year equals 7 dog years ratio

This is actually a myth! Popularized in the 1950s, this misconception was an overgeneralized statement based on assumptions of average human and dog lifespans. At the time, the average human lifespan was around seventy years and the average dog lived about ten years.

What is 42 in dog years? ›

Using this human years to dog years calculator: A two-year-old dog is 42 human years old. A five-year-old dog is 56.8 human years old. A 10-year-old dog is 67.8 human years old.

How many years do dogs live? ›

The ageing profile of dogs varies according to their adult size (often determined by their breed). Smaller dogs often live over 15 to 16 years. Whereas the medium and large-sized dogs typically live for 10 to 13 years, and some giant dog breeds such as mastiffs often live only for 7 to 8 years.

How old is 1 in cat years? ›

How many cat years are in a human year? The first year of your cat's life is considered the equivalent of 15 human years. The second year adds nine more human years, so 2 cat years are approximately 24 human years. After this, each additional human year is four 'cat years' i.e., age 3 will be 28 human years.

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