How old is my dog in human years?

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If pooch parents could have one wish, it’d be that our dogs could live as long as we do. They enrich our lives with fun, laughter and a whole lot of love.

Unfortunately, this isn’t possible, and our pups age at a rapid rate compared to us humans. A child just entering their teenage years would be considered in their youth and prime of their life, whereas a 13-year-old pooch would be classed as an elderly grand-paw.

Just a couple of years can make all the dif-fur-ence to your dog’s appearance, health and behaviour. That’s why it’s incredibly important to cherish every single moment you get with your dog, even if they do drive you up the wall!

We’ve all heard the age-old theory that 1 year for a dog is equal to 7 human years, but is this true?

How do you work out a dog’s age?

To begin, we’re going to immediately squash the concept of 1 dog year correlating to 7 human years, as this isn’t true and there’s no scientific evidence to back this up. A year for a human is incredibly dif-fur-ent to a year for a dog.

The general consensus is that the first year of an average, medium-sized pooch life works out at approximately 15 human years. When they reach their 2nd birthday, add on another 9 years and every year after that will be another 4/5 years added on.

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During their puppy years, they grow at a rapid rate. This is no surprise as we know a lot happens in that first year of their life, they approach everything with open arms and it’s an entire year of new experiences. They also grow physically very quickly too.

Primarily, these statistics are based on physical factors, we can assume that a 1-year-old pooch is equivalent to a 15-year-old human teenager due to their bounds of energy, they’re beginning to reach sexual and social maturity and all their adult teeth have come through.

So, according to this formula, a 2-year-old, medium-sized dog will be about 24 human years-old. When they reach the grand old age of 10, the dog will be around 60 human years old. This clearly shows a massive diversion from the 1 dog year being 7 human years theory.


However, there has been another study into how we calculate how old our hounds are. Researchers performed DNA tests on a cohort of 104 Labradors whose ages spanned a 16-year range.

This compared the epigenetic clocks of dogs to a human’s epigenetic clock. Epigenetics refers to the study of how various factors can cause changes that impact how your genes work.

It’s already a known fact that dogs and humans experience a lot of the same signs of aging, such as arthritis, obesity and diabetes, and this study demonstrated how both people and pooches experience similar molecular changes, and the life stages match up. Although, a dog’s epigenetic clock will be ticking at a much more rapid rate.

To conclude the study, the researchers came up with a formula for dogs above the age of 1, to determine how old they are in human years.

Just a quick warning, we’re going to get a bit mathematical here.

So, the formula is, a dog’s human age is approximately: ‘16ln (dog age) + 31’. Confusing right?

Essentially, to use this formula, you first need to take the natural logarithm of your dog’s real age, which can be worked out on this handy calculator. Just type in your dog’s age and the calculator will do the work for you.

For example, if your pooch is 4 years old, their natural logarithm will be 1.3862943611198906. The next step is to multiply their natural logarithm by 16, so 1.3862943611198906 x 16 = 22.1 (approximately). Finally, just add 31 onto the total, so 22.1 + 31 = 53.1. This means that if you have a 4-year-old pooch, they’d be around 53 in human years!

Obviously, both of these methods for working out your dog’s age are estimates based off of many variables, but neither of them can be entirely accurate. Problems arise as every dog breed will age at varying rates, so it’s impossible to completely tell as the answer will be different from dog to dog.

The study is also misrepresentative of dogs in general, as it has only been based on Labradors, which will age a lot dif-fur-ently than for example, a tiny little Chihuahua would.

Small dogs tend to live a lot longer than larger breeds. Generally, when a dog reaches the age of about 6, they’re considered senior pooches, but this age would be verging on past 7 for miniature dogs and around 5 for larger ones.

However, this is only a classification, we know that our pups still have a lot of life, fun and energy left in them at the mere age of 6. Classing dogs of this age as seniors is pretty much based on how rapidly our dogs age compared to humans, and vets often start to see more age-related ailments cropping up from these ages.

Despite this, we might see that a giant dog such as Great Dane is likely to live longer than a medium-sized dog such as a Bulldog, due to the health problems that arise with brachycephalic (flat-faced) breeds.

Until our dogs can talk to us and tell us exactly how old they are, how they feel and if they’re unwell, we’ll probably never know exactly how old they are in human years.

Why do smaller dogs live longer than larger dogs?

The domestic dog has a huge number of different breeds in various shapes and sizes.

The question of why small dogs live longer than larger dogs is pretty baffling, and it doesn’t have a definite answer. At the moment, it just appears to be a fact of life.

Strangely, dogs seem to be the outcasts in the animal world in this sense, as typically, larger mammals such as elephants outlive tiny animals like mice. But why is that?

Every dog breed is completely unique, and it’s true that large and little dogs are prone to different diseases, large dogs being more likely to develop musculoskeletal, gastrointestinal and neoplastic disorders and smaller dogs more likely to get endrocine-related illnesses, according to this study.

Aging seems to begin at the same point for both small and large dogs, but then larger breeds continue aging at a more rapid rate. Once senescence begins, which is the deterioration you see when you age, larger breeds experience it quicker.

The underlying reasons for why this happens are inconclusive, it’s just something that happens. Larger dogs are also more likely to develop age-related illnesses, such as arthritis due to the increased pressure their higher body mass puts on their joints.

A 2013 study suggests that large breeds are also more susceptible to cancer, and as a result death, due to their size. This is because their rapid rate of growth means they’re more likely to develop the out of the ordinary cell growth seen in some cancers.

It’s peculiar how larger dogs age faster than smaller dogs, as during their puppyhood it seems to be the opposite way round. Puppies stop growing (both physically and mentally) at different rates, and smaller dogs usually grow up and reach their adulthood before larger dogs. It often takes larger dogs a full two years to reach their full size, possibly even 3 years when it comes to their mental maturity!

What about if I don’t know how old they are in dog years?

If you’ve rescued a dog, or even a puppy, it might be hard to determine their exact age in dog years, never mind human years.

Many rescue dogs come with an unknown history and heritage, so it’s pretty impossible to know their entire background, sometimes you might not even know what breed they are!

Despite this, there are ways to make an estimate of how old they are. A senior dog will be easier to spot as they show signs of aging through cloudy, glazed eyes, grey hair (likely forming around their muzzle like a beard), stiff muscles and signs of pain.

However, teeth are usually the best way to identify a dog’s age, so take a good look at their gnashers.

Tooth timeline:

6-9 weeks: All their baby teeth will have come through, watch out, these ones are so sharp they’re like needles!

6-8 months: A full set of permanent teeth should be here at 7 months, and they should look in great condition, a lovely set of clean pearly whites.

1-2 years: The teeth should still be in good nick, but they may have begun to dull down and yellow towards the back.

3-5 years: The teeth might start looking a bit shabby now, plaque and tartar will be building up across the full set.

5-10 years: Signs of disease may start to show, and their teeth will be looking worn, yellower and dull

10-15 years: During their senior years, the teeth will have a big tartar build-up, and some may even be missing

Where did the 7-year theory come from?

It’s quite strange how quickly myths can be spread and believed, for example, it’s widely believed that dogs are colour blind, only seeing in black and white, but this is by no means true.

A similar spread of myth has happened with the 1 dog year equals 7 human years concept. This theory has no evidence, it was just quickly taken as fact and perpetuated to the extent that it’s become a universal, widespread belief.

It’s suggested that the formula started by dividing a human’s average lifespan of 80 years old with a dog’s, which is around 12 years of age. It appears to have been created to essentially emphasise how dogs do age at a more rapid rate than humans.

It’ll be incredibly hard to completely eradicate this myth, as it has been believed by so many people for so long. Realistically, it doesn’t really matter how old your dog is in human years, as long as you know they’re happy and healthy!

Emotional maturity

As we know, dogs all grow physically at differing rates, and some enter the senior stage of their lives a lot sooner than others do.

Puppies generally stop growing when they are about 1 year old, but again this varies from dog to dog and for most dogs, their emotional maturity won’t align with their physical maturity. Many puppies can be fully grown physically, but still act like a puppy mentally. Some pooches might not reach full maturity until they’re about 3 or 4 years old!

This is very similar to how humans mature emotionally. An 18-year-old is considered to be an adult, ready to step out into the world, but they probably won’t be fully mature in their heads for several years after this. The same applies to pooches. You might have a 1-year-old pup who is fully mature socially and sexually and has reached full size, but they’ll be up to puppy mischief and mayhem until way beyond their 3rd birthday.

What is old?

This is a tricky question. Some people consider as young as 55 to be senior, whereas some would add several years onto that! Senior status in the canine world varies too.

As stated, smaller dogs reach seniority at a much older age than larger dogs. Many dogs are still as sprightly as ever at 10 years old and you would never dream of called them a senior pooch.

Signs of aging include:

  • Vision loss

  • Hearing loss

  • Weight gain

  • Fatigued, inactive and reluctant to exercise

  • Missing teeth

  • Loss of skin elasticity

  • Hair loss

  • Mental decline, not as sharp as they once were

  • Age-related illnesses

Age related illnesses include: arthritis and overall joint pain, respiratory problems, diabetes, heart disease, cancer, doggy dementia to list a few.

Oldest dog world record

The current world record for the oldest dog in the world is an Australian Cattle Dog named Bluey, who lived to the whopping age of 29-years-old!

Check out our huge list of the longest living dog breeds, it definitely backs up the theory that the smaller pups have a much longer lifespan than larger dogs.

Can I help my dog live longer?

We all want our dogs to live long, healthy and happy lives. Luckily, our dogs are living longer than ever before, all thanks to better ways to care for your dog and improve their quality of life and advancements in expertise and veterinary care.

Being proactive is the best thing dog parents can do to help your four-legged friend enjoy every second of life and live healthily for as long as possible.


Food is the first step to keeping your dog’s overall health in tip-top shape. Many people are often keen to feed themselves a healthy, balanced diet, as we understand that putting the best stuff into our bodies will allow us to get the best out of it. It can often be forgotten that the same goes for our poor pups, the best quality food will provide them with the best quality of life.

Providing your pup with a diet suited to whatever age they’re at is essential, as puppies have a totally dif-fur-ent set of things they require from their food to a senior pooch.

Pure creates a tailored menu for your pooch, ensuring your pup will get everything they require for their specific lifestage, just enter your dogs age (their dog age not their human age!) and Pure will do the rest. A completely tailored recipe will be curated in accordance with your dog’s lifestage, allergies, ailments, breed and size to equip them with a food that is packed with all the ingredients and nutrients they need. Your dog’s recipe will continue to change and develop as they age to make sure its perfect for your pooch.

Full of protein, vegetables and containing absolutely no nasties, Pure will support your dog’s development, maintain their bodily functions and support their immune system to fight off age-related illnesses.

Functional ingredients such as omega 3 fatty acids are an important part of a Pure recipe, as they work to decrease any inflammation in the joints, helping prevent the onset of debilitating conditions such as arthritis that commonly occur when your dog grows older. Also, omega 3 is recognised to help brain cells, memory and overall cognitive function.

Keeping your dog’s mind healthy is all a part of maintaining their physical health, and their diet is a great way to help prevent cognitive decline and conditions such as doggy dementia.


Most dogs love their walkies, and luckily, a walk a day should keep the vet away!

Ensuring your pup gets the appropriate amount of exercise for their breed and age will help to build muscle and help their mobility as they grow older.

Age-related illnesses such as arthritis can cause your pooch serious pain, so it’s crucial that you know your dog’s limits, too much or too little exercise can cause damage to their joints.

When you first get a puppy, you must work out how much exercise they’ll need, as too much exercise will damage their joints and increase the likelihood of your dog experiencing the early onset of arthritis, and therefore aging much quicker than they should.

The appropriate amount of exercise alongside a balanced, nutritious diet filled with joint-supporting ingredients will help your dog keep them healthy and fit.

Mental enrichment

When we get older, our brain and mind begin to decline. We want to keep the cognitive function of our clever canines quick and sharp, so their minds are kept young for longer.

Alongside a great diet with great ingredients and the suitable amount of exercise, enriching the environment your dog lives in will work wonders for keeping your dog young. Snuffle mats, lickimats and puzzle toys are all brilliant ways to stop your dog from getting bored and keeping their mind ticking. Check out our full list of boredom busters here. Even try teaching them a trick with short, snappy training sessions, don’t listen to the myth, you can teach an old dog a new trick!

An even easier enrichment activity, and an incredibly effective one, is just allowing your dog to sniff everything (and we mean EVERYTHING) on a walk. It allows your dog to relax, take in the air and navigate the walk themselves, as they have an impeccable sense of smell and it’s their main method of viewing the world.

Senior pooches will see a massive benefit from this as they probably can’t walk for miles and miles, but a walk around the street with the time spent sniffing will be plenty enough to keep their brains whirring.

Vet check-ups

Finding the balance of your dog living for a long time while continuing to be happy and pain-free is vital, and it mostly relies on maintenance and management.

An annual check-up with the vet (or even every 6 months) is a proactive way of understanding what your dog is like when they’re in good health so you can stay on top of their condition if you or the vet spot any abnormalities.


It can feel like our pet’s lives have been on fast forward, in the blink of an eye they’ve gone from rambunctious little pups to chilled out oldies.

Having a ruff guideline on your dog’s age and signs of aging is always good to know, but try and let the upsetting prospect of your dog getting old leave your mind.

The fun, laughter and love you share with your pooch will be memories to last a lifetime, and in your eyes your pooch will probably never get old, you’ll no doubt treat them as a young puppy for the rest of their lives.