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If you’ve always estimated your canine friend’s age in ‘dog years’ by multiplying their human age by seven, new research has found that you’ve been doing it all wrong.

While no one really knows where this formula came from (it has been denied by vets for a while), a new study from the University of California, San Diego has found that it is definitely not the correct way to work it out.

Researchers performed a genetic analysis of dogs and humans to identify how they age over time, and found that dogs initially age faster when compared with humans and become the equivalent of human middle age within a few years.

However, this slows down dramatically with a dog ageing just two decades across the next 10 human years.

How to work out your dog’s age

The exact formula these scientists have come up with is: 16 x ln(dog's age) + 31.

This formula can be used for any dog aged older than one, although the research team only focused on Labrador retrievers in their study.

To work out the formula, work out your dog’s human age first and press ‘ln’ on your scientific calculator (most smart phones with calculators turn into scientific calculator when rotated horizontally – just be sure to have your auto rotate setting switched on). Once you have a scientific calculator press 'ln', put in your dog’s age and press equals.

Multiply this number by 16, press equals, and then add 31 and this is your dog’s age.

Using this formula, a three-year-old dog is 48.5 human years, an eight-year-old dog is 64.2 human years and a 15-year-old dog is 74.3 human years.