Although the age-old trick is to multiply your dog’s age by seven to know how old your dog is in human years, that trick might be outdated.

A 2019 study reexamined assumptions around dog aging and looked at physiological factors that could help determine the age of your dog.

Now, there is a calculator that you can use to learn your dog’s age in human years.

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The dog age calculator from Better Pet requires you to first know what age your dog is in dog years. If you adopted your dog, it can be tricky to figure out your dog’s age. You can try to find this information by observing your dog’s teeth and coat. Veterinarians can help you find an approximate age of your dog’s teeth by looking at the ridges.

After you know your dog’s age, you can use the calculator to put in what size of dog you have: small, medium or large. For example, if your dog is 5 years old in dog years and is a small dog (20 pounds or under), the calculator determines that, in human years, your dog is 36 years old. Five-year-old medium-size dogs (21 pounds to 50 pounds) are 37 years old, while large dogs (more than 50 pounds) would be 40 years old in human years.

Better Pet said that smaller pets have a better chance of living longer because they do not have the same propensity for health problems. Due to better understanding of physiological factors, the old rule of multiplying your dog’s age by seven to get his age in human years doesn’t work. Instead, “This new equation multiplies the natural logarithm of the dog’s age by 16 and adds 31.”