How old is a 15 year old dog

Dog Age Chart: How Old is My Dog in Human Years?

How old is your dog in human years? We used to simply multiply a dogs age by seven.However, thiscalculation isnt socut-and-dried.See our dog age calculator and chart to discover your dogsage.

Do Dogs Age 7 Years to Our 1Year?

The easy way to calculate a dogs age is to take 1 dog year and multiply it by 7 years. This is based on the assumption that dogs live to about 10 and humans live to about 70, on average. For example, a dog that is 5 years old is 35 human years.

Contrary to common belief, dogs do not age at a rate of 7 human years for each year in dog years.The number of human years piles onto a dogs life more quickly during the dogs rapid growth to maturity.

That said, this isnt a bad way to go from a health perspective because it helps us humans realize that our dogs arent the same aschildren.

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 ofage.

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

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

How to Calculate a Dogs AgeProperly

Statistics from pet insurance companies, breed club surveys, and veterinary hospitals have helped us learn more about how dogs age. According to the American Veterinary MedicalAssociation:

• The first year of a medium-sized dogs life equals approximately 15 years of a humanslife.
• The second year of a dogs life equals about nine years for ahuman.
• After that, every human year equals approximately four or five years for adog.

Dog Age Calculator: Dog Years to HumanYears

If we think like a dog, heres how a dogs age compares to a humans age! Note that this is still not a perfect calculator. There are many variations based on a dogs breed, their background, and their size.Note that this calculator is for a medium-sizedbreed of dog. Consult the chart below to see the differences between dogs of different sizes(small, medium, large, giant). Itshould give you a good sense of where your dog is in the development/agingprocess.

• Small Dog: 20 pounds orless
• Medium Dog: 21 to 50pounds
• Large Dog: 51 pounds to 100pounds
• Giant Dog: Over 100pounds

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

RelatedArticles

How old is your canine companion? Tell us in the commentsbelow!

Dog Years Calculator

Quick navigation:

1. Using the dog years calculator
2. How do dog years work?
3. Dog years to human years formula
4. Dog age chart
5. Limitations of the dog age calculator
6. The myth of multiplying dog age by seven to get the human age
7. How many dog years are in a human year?

Using the dog years calculator

This dog age calculator makes it easy to answer the question how old is my dog in human years? If you know your dog's age, just enter it as either a number of years or months. If you don't know the age, but know the dog's birth date, enter it instead and our tool will calculate the dog age in calendar years for you. Finally click "Calculate Human Years".

The output of the calculator is the number of human years, and the equivalent human age in years and months. The tool converts dog years in human years using the formula below.

How do dog years work?

The idea of 'dog years' and 'human years' is to more easily assess what stage of life your dog is: puppy, junior, adult, mature, senior, or geriatric. While different animal associations and veterinary associations might have charts and guidelines for that, for regular people it is much easier to understand when the dog's age is converted to the age of a human in an equivalent phase of physical development. For example, 9 years in dog years are equal to 66 human years, meaning that a 9-year old dog is roughly equivalent to a 66-year old person. Some use the term 'dog years' to mean 'human age equivalent years' while the scientific literature prefers the term 'human years' as more accurate.

The application of this idea is mainly in veterinary work, but it can also help dog owners appreciate the stage of life their pet is in, the physical difficulties that may entail, and so on. Both human and animal life spans have increased over time due to superior care and the availability of more economic resources which can be dedicated to animal healthcare. Continued improvements are unlikely with the current state of medical science, but should they become a reality, we would need to change the way we convert dog years to human years.

Dog years to human years formula

The dog age to human age conversion formula we use in this dog years calculator is based on research by Wang et al. (2020) ^[1]. Its derivation comes from the comparison of human DNA methylation changes with those of dogs. Methylation is experienced by mammalian genomes as they age and can serve as a sort of epigenetic clock. It is linked with life spans of various species and hence can serve as a model of aging.

In the equation above, HumanAge is the age equivalent of a human in years whereas DogAge is the age of the dog measured in calendar years. ln is the natural logarithm function. For example, a 12 year old dog will be nearly 71 in human years.

Dog age chart

The dog years chart below presents the equivalent human age for a given dog age. Since it was calculated using this dog years to human years calculator, it is subject to the same limitations as the tool itself.

The chart can be used to tell how old is 4 in dog years, or the reverse, e.g. what is 9 years in dog years.

Limitations of the dog age calculator

Since the research used to construct this tool was carried on 104 Labrador retrievers spanning a 16-year age range, it may have lower validity for other dog breeds. It should be used with caution for breeds that exhibit a typical lifespan much different than that of Labrador retrievers. E.g. it might work well for a Boxer, a Pitbull or a German Shepherd, but it will probably slightly overestimate the human equivalent age of a Yorkie, a Labradoodle, a Maltipoo, a Cockapoo, a Shetland sheepdog, or a Jack Russell.

Additionally, the dog years equation does not support dog age less than approximately 1.8 months. For this reason a dog age below 1.8 months is calculated as 0.3 human years, which should serve as a rough approximation.

The myth of multiplying dog age by seven to get the human age

For many years the standard advice was that in order to get the human years equivalent, one needs to simply multiply the dog age by seven. So a two year old dog would have a human age equivalent to a 14-yeard old adolescent. However, this advice was never scientifically backed. For example, most dogs would reach sexual maturity between six and twelve months old, well before the two-year mark suggested by this simple approach.

Some believe that this basic advice was given to dog owners so they would remember they need to bring in their companions for a regular check up at the veterinarian office at least one a year. If one dog year is equal to seven human years, that actually sounds like conservative advice.

How many dog years are in a human year?

Understanding the non-linear monotonic relationship between dog years and human years means asking questions like how many dog years are in a human year is meaningless. There is no single number which answers that question. To answer it, one needs to present the functional relationship across the entire life spans of both dogs and humans, just like in the dog age chart.

References

1 Wang T. et al. (2020) "Quantitative Translation of Dog-to-Human Aging by Conserved Remodeling of the DNA Methylome", Cell Systems, DOI: 10.1016/j.cels.2020.06.006

Dog age calculator: how old is my dog in human years?

Dogs experience life stages similar to humans, but they progress at different rates. For example, puppyhood lasts less than a year compared to human childhood, which lasts around 10 to 12 years before puberty. Aging is correlated to breed, as small breeds tend to develop faster and reach seniority slower than large-breed dogs.

1. Puppy

Although people still consider a dog a puppy until its around 2 years old, its only a puppy developmentally until 6 months. During their first half-year of life, your dog will grow exponentially, gaining and losing all of their baby teeth and achieving most of their height during this timespan.

2. Junior

Your dog reaches their challenging adolescent period between 6 months and a year old. Although they may still act like a puppy, theyre rapidly undergoing sexual development and will typically reach reproductive maturity between 9 months and a year.

3. Adult

After their first birthday, your dog will officially be considered an adult. At this time, you can switch them to adult food if you havent already, and theyre safely eligible to have puppies unless theyve been spayed or neutered. With most of their linear growth behind them, your dog may continue to fill out and gain weight during their second year of life, losing the gangly appearance they might have had as puppies.

The last three life stages arent as straightforward as the first three because they depend on your dogs breed.

4. Mature

A dog is mature or middle-aged when its metabolism begins to slow. At this point, make sure that they dont becomeobese. You might want to talk to your vet about switching to a low-calorie food.

5. Senior

Your dog is considered a senior during the last estimated 25% of their lifespan. For example, a dog that lives about 12 years would be a senior when it turns 9. You might consider switching to a senior diet if you havent already since dogs dont need as many calories or fat as they did in their younger years.

6. Geriatric

Not all dogs live long enough to be considered geriatric, the final period of life where age expectancy is exceeded. As they rapidly slow down, they might develop cognitive problems such asdog dementia, so youll need to account for limited mobility, making sure they dont jump down from furniture and carrying them when traveling a long distance. Still encourage them to exercise, but know their limits and dont force them.

Dog Years To Human Years: Dog Age Calculator & Chart

It was once thought that one dog year is equal to seven human years, but this is not true!

Different dogs age at different rates. It isnt quite as simple as saying that for each year that a dog ages, they age the equivalent of seven human years.

Generally the bigger the breed, the quicker they age and the shorter their lifespan.

So how does converting dog years to human years work?

Keep reading to find out just how many human years are equal to one dog year. We also share how to work out your dogs human age.

Dog Age Calculator

Converting dog years to human years isnt as simple as multiplying by 7.

There is a much more complicated equation to calculate how old your dog is in human years.

Use our handy human years to dog years calculator below to work it out without having to do any of the maths yourself!

Simply select their current age (in human years) and then select their gender and size.

Dog Age Chart

Many people want to know how old their dog is in human years.

The good news is that until around three years old, most dogs age at the same rate. At three years old most dogs are around 28 human years.

After this age, larger dogs start aging more quickly than smaller dogs.

A good rule of thumb is that the smaller the breed, the longer their average lifespan. A 10 year old Bull Mastiff is the equivalent of 71 in human years, but a 10 year old Jack Russel Terrier is just 56 in human years!

Take a look at our chart below to work out how old is your dog.

(c) AKC Chart

How Do Dog Years Work?

Dogs have a much shorter lifespan than humans.

Each year of a dogs life is equivalent to more than just one human year.

One dog year can be the equivalent of 4 to 16 human years depending on their size, breed, gender and health.

The easiest way to compare the ages of dogs is to look at which stage of life they are in.

A dogs life is split up into six different stages based on their physical and mental characteristics. Each dog breed will spend a different period of time in each stage of life, and therefore has a different lifespan.

These six life stages are:

1. Neonatal (< 2 weeks)
2. Puppy (< 6 months)
3. Junior (6-12 months)
4. Adult (12+ months)
5. Mature
6. Senior

1. Neonatal

This is when your dog is a newborn puppy and includes the first 2 weeks of their life, no matter the breed or size of the dog.

2. Puppy

This is the period where your puppy comes home and is learning and growing. Dogs are considered puppies until they are around 6 months of age.

3. Junior

This is equivalent to your dog being a teenager. This stage lasts for 6-12 months, until they are finished growing. Larger breeds will be considered junior for longer as they continue growing for much longer than smaller breeds.

4. Adult

Once your dog has finished growing, they are officially adults. For small breeds this will be from 9-12 months, but large breeds will keep growing until they are as much as 2 years old.

5. Mature

Dogs tend to relax and want a quieter life as they hit middle age. This can vary from dog to dog but is usually around 4-5 years for larger breeds and 6-7 for smaller breeds.

6. Senior

As your dog ages they will become slower and show physical signs of aging like greying hair, reluctance to exercise as much and weight gain.

Smaller breeds wont hit their senior years until they are more than 10 years old.

Larger breeds will be considered senior from as young as 6 years old.

There is a general trend that the larger the breed, the less time they spend in the mature and senior life stages. This is true even though it takes them longer to grow and become adults.

Dog Years To Human Years

1 dog year to 7 human years doesnt work as a conversion rate.

So, how does converting dog years to human years actually work?

The answer is that it depends on what size category your dog falls into.

Dog breeds are divided up into 4 main size categories according to their weight when fully grown:

• Small 0-20 lbs. (e.g. Dachshunds, Pugs and Shih Tzus)
• Medium 21-50 lbs. (e.g. Cocker Spaniels, Australia Cattle Dogs and Basset Hounds)
• Large 51-100 lbs. (e.g. Labrador Retrievers, German Shepherds and Boxers)
• Giant: 100+ lbs (e.g. Bull Mastiffs, Great Danes and Rottweilers)

The general rule for conversion is that the smaller the breed, the longer their lifespan.

For a smaller dog, one year can be the equivalent of around 4 human years. For a giant breed, one year can be the equivalent of around 6-8 human years.

This difference is obvious when you compare one of the smallest breeds, to one of the largest.

Chihuahuas have an average life expectancy of 14-16 years, while a Great Danes average life expectancy is just 7-10 years. Medium sized dogs like Pitbulls will live for 8-16 years.

This has long confused scientists, because there is a general rule that the smaller the mammal, the shorter their lives. This is the reason why an elephant lives much longer than a mouse, and why a horse lives longer than a hamster!

So why do dogs break this rule?

There are currently three working theories.

The first theory is that bigger dogs age faster. This means you will see signs of old age in bigger dogs from a much younger age than you will in smaller breeds. These signs can include:

• Greying around the muzzle
• Arthritis and joint pain
• Having less energy
• Putting on weight more easily

The second theory is that bigger dogs start aging earlier in life.

Bigger dogs have a higher base level of a hormone called IGF-1. This hormone is associated with aging and age-related diseases like cancer or heart disease.

Lowering levels of IGF-1 has been shown to slow the rate of aging and extend an animals lifespan.

The final theory is that larger dogs have a higher risk of death throughout life, not just later on in life. The main explanation for this is that when the lifespan of dogs of different sizes was investigated, accident as cause of death was not excluded.

The research paper did later adjust for accidents, but it still showed that larger breeds aged faster.

Is 1 Dog Year 7 Human Years?

Since the 1950s there has been a long-standing myth that for each year of a dogs life, they age by exactly 7 human years.

This would mean that:

1. 1 year old dog is 7 human years old
2. At 2 they are 14 human years
3. and so on

It is thought that this rule was first established because dogs would live approximately 10 years, and humans 70.

To begin with this was a good rule of thumb for a quick calculation from human years to dog years. However, it is now understood that there is a lot more to it than this straight forward conversion of dog years to human years!

A study done by the Department of Medicine at University of California in 2019 showed that dog years to human years do not work that like.

They showed that there is a non-linear relationship between dog and human years.

In more straightforward terms, it is not as simple as 1 dog year equaling 7 human years.

The research showed that dogs reach adulthood much quicker than humans do, but then their aging slows down during adulthood. Dogs only reach their senior years in the last quarter of their lifetime.

All dogs reach their teenage years by one year old.

In other words, all dogs are roughly 15 human years old on their first birthday.

Following this, most dogs will reach the mature life stage by 5-6 years of age. This stage is the equivalent of a humans middle age, making most dogs somewhere in their 40s in human years by the time they are 6 years old.

After this age, dogs of different sizes start aging differently, with large breeds aging much quicker than smaller ones.

A Chihuahua might not be considered senior until they reach 10. A giant breed, like a Great Dane, is called senior from as young as 6 years old.

How Old Is My Dog?

The best way to estimate a dogs age is by looking at their teeth.

By 8 weeks old, a puppy will have all their baby teeth. These teeth are very sharp and often compared to sharks teeth because of how pointy they are! Your puppy will have all of these teeth when you bring them home.

Puppy teeth will gradually be replaced by permanent adult teeth and will be completely replaced by the age of 7-8 months.

Permanent teeth are bigger and less pointed.

Adult teeth are bright white and completely clean from 9 months to the age of 2.

Over time adult teeth will start yellowing and brown tartar will build up on the surface. This will be obvious from around 3-5 years of age. By 7+ years old there will be signs of wear and tear to the teeth, which look like missing or loose teeth, heavy tartar and worn-down teeth.

Teeth arent the only way to age a dog, but it is the most reliable method.

There arent many other signs of age, especially in younger dogs.

Signs of aging in senior dogs includes the development of cloudy eyes and gray hair around their muzzle, paws, and stomach.

Cloudy eyes (lenticular sclerosis) do not affect your dogs vision, but they are associated with old age. Cloudy eyes are usually a sign of a dog being over 7 years old.

Another sign of old age in dogs is gray hair developing around their muzzle, paws, and stomach. This is especially obvious in dogs as they become older than around 8 years of age.

As dogs grow older than 9, they may also experience stiffness and arthritis in their limbs. You may notice they have difficulty jumping or standing up, more so after they have been laying still for a long period of time.

Things You Can Do To Help Your Dog Live Longer

There are some factors we can control to help our dogs live longer and healthier lives:

• Monitor their daily food intake and feed a balanced diet.
• Regular exercise.
• Keeping on top of vaccines and preventatives.
• Taking your dog for an annual health check.

Approximately 25-30% of dogs in the US are considered obese. Obesity can reduce a dogs lifespan by 1-2 years, so keeping your dog at the right weight is one of the easiest ways to help them live longer.

Being obese not only decreases your dogs lifespan, but also makes them unhealthier and uncomfortable.

Keep their weight under control by monitoring their daily food intake and making sure they only get the right amount of food for their weight and activity level.

Exercise is another way to control your dogs weight and keep them healthy.

Although you cant control everything in your dogs life, keeping them a healthy weight by feeding a balanced diet and getting regular exercise will help to extend their lifespan.

Keeping on top of parasite prevention and attending regular vet health checks are also helpful.

Making sure your dog is kept up to date on both their vaccines and preventatives is an easy way to keep them safe from diseases.

This comes hand in hand with taking your dog to the vets at least once a year for a complete health check. Vets can pick up on things you might not have otherwise been aware of. They can perform health checks on any lumps, bumps, and scrapes, as well as checking in their mouth, ears, and eyes.

Key Points

• 1 dog year is not equal to 7 human years. This once common belief, has recently been debunked as there is a non-linear relationship between dog and human years.
• One dog year can be the equivalent of 4 to 16 human years depending on the dogs size, breed, gender and health.
• All dogs are roughly 15 human years old on their first birthday.
• After three years of age different size dogs start aging at different speeds.
• Big dogs age faster and reach old age earlier than smaller ones.
• The smaller the dog breed, the longer their lifespan. Small breeds like Dachshunds tend to live up to 15 years, whereas giant breeds like Bull Mastiffs only live on average 6-7 years.
• The easiest way to age a dog is by looking at their teeth, but you can also tell a senior dog by looking for gray fur, cloudy eyes, and stiff limbs.
• To help our dogs live healthier for longer we can make sure they maintain a healthy weight, get enough exercise, stay up to date on vaccines and parasite control and receive regular health checks.