A senior chocolate Labrador looks into the camera

Use our dog age calculator to find your pup's age

© Unsplash - Jairo Alzate

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

By Natasha James Content Writer

Updated on the

Have you ever wondered how old your dog is in human years? We've put together a useful dog age calculator so you can work out the exact age of your pup.

Different breeds of dogs age differently so while one dog might very clearly be in their senior years, a different breed born on the same day could still be frolicking about like a spring chicken!

Curious to know more? We have all the info you need right here.

How many years do dogs age per human year?

Historically speaking, people simply multiplied their dog’s age by seven to find the equivalent age in human years, but there’s no science to back this methodology up. It’s likely that when the concept was first dreamt up back in the 1950s, animal behaviourists simply ascertained that dogs live for around 10 years and humans live for around 70. Simple but far from accurate.

New research has revealed that a dog’s age doesn’t correlate in jumps of 7 at all. Almost all dogs will be able to rear puppies at the age of 1, after all.

How do you calculate a dog's age?

A 2019 study has suggested a new formula for calculating a dog's life span that is far more accurate. It looks like this:

•    First year of a dog’s life = 15 human years
•    Second year of a dog’s life = + 9 years
•    Each subsequent year = four or five human years

So, a six-year-old dog will be the equivalent to a human in their early 40s. 

But, the real answer is more complex than that and shows big differences in breeds. An 8-year-old Great Dane, for example, will be a senior dog and have all the trappings that come with age (reduced movement, grey hairs, joint pain) whereas an 8-year-old Jack Russell Terrier could have years before they experience any ageing issues.

How do researchers come up with the figures?

Researchers at the University of California San Diego School of Medicine studied dog DNA and the ageing process using Labrador Retrievers. They came up with an even more accurate (and more complex) way of ascertaining a dog’s life span. The experts used an epigenetic clock to measure age. They mapped molecular changes and looked at patterns called methyl groups in a dog in relation to a human.

This is the formula: (human_age = 16ln(dog_age) + 31

Fairly confusing if you’re not a maths whizz so here’s our dog calculator so you can work it out for your dog.

Dog age calculator: here's how to find out how old your dog is

Calculate your dog's age in human years ©Wamiz

Why do smaller dogs live longer than larger dogs?

Smaller dogs tend to live considerably longer than their big dog counterparts. A fact that has puzzled scientists and animal specialists for years. After all, in the rest of the Animal Kingdom, larger animals tend to live longest. A huge bowhead whale can live for 200 years whereas a smaller mammal, such as weasel, may only live for a year or two. 

So, why do smaller dogs live longer? Well, it’s still not completely clear but scientists suggest that larger dogs may be more likely to contract serious, life-limiting illnesses than smaller dogs. Studies are ongoing so when we know more, we’ll be sure to update you!

In the meantime, whether you have a sprightly 14-year-old Shih Tzu or a languid 9-year-old Bullmastiff, make the most of your pup and enjoy the beauty that comes with their advancing years.

Does your dog have Old Dog Syndrome? Here are the signs.
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