Dogs are calendar year older too but when the clock strikes midnight on New Year’s Eve, is your dog toasting to a new year or seven New Years? Unfortunately, the answer isn’t quite so easy. In this article, we’ll look at some more sophisticated ways to determine your dog’s age.


  1. Determining your dog’s actual age:-

Learn your dog’s age in actual years. Knowing your dog’s actual biological age is important to calculate his age in dog years. It also helps you to take care of your dog well during his life that is usually based on age, such as when to spay or neuter and when to change to a senior diet. However, if you don’t have this information readily available, there are some other ways to determine his age. 

Most of these methods involve an investigation of several physical characteristics including the condition of the teeth, size, coat condition, and eye conditions.

  1. Inspect your dog’s teeth:-

Look at the stage and the condition of the teeth. Determine the stage your dog’s teeth are at. Puppies may usually have all of their baby teeth by the time they’re 8 weeks old and will have all of their permanent teeth by the time they are 6-7 months old. Your dogs will start getting their permanent canine teeth,  the longest ones, usually right at 6 months old, which makes this the easiest time to accurately age a puppy. If they have all of their permanent teeth and they are wide and clean, they could be up to one and a half to two years, but probably around one year old.

  1. Assess the condition of the teeth:-

Between the ages of 1 and 2 years old, many dogs may start to show some yellowing on their back teeth. Tartar buildup starts shortly after this. Many dogs will start to show wear on their incisors, between 3 and 5 years. Significant tartar buildup with evidence of gum disease(look for red, inflamed gums) can be seen after they are five years old. Missing teeth will ultimately mean that your dog is a senior and may need some medical care. The stage and condition of your dog’s teeth can help you to give a good estimate of your dog’s age. Remember, there are many factors that can affect your dog’s appearance including breed, genetics, chewing behavior, and history of medical care.

  1. Assess your dog’s size and growth:-

If the dog is continuously growing, then he is less than one and a half to two years old, depending on his overall size. Small dogs can reach their full height and length by around one year of age, but large dogs may take some time until they are 18 months to 2 years old. 

  1. Assess your dog’s muscle tone:-

Young dogs have more muscle definition than older ones. Older dogs can be a little bonier or fatter due to decreased activity. Watch your dog when he plays around, he moves with a little more stiffness; this is also a sign of aging.

  1. Examine your dog’s coat:-

Young dogs usually have soft, fine coats. Older dogs may have thicker and coarser fur that can sometimes also be oilier. Senior dogs may also have grays or patches of white, particularly around the snout.

  1. Inspect your dog’s eyes:-

Younger dogs tend to have bright, clear eyes without tearing or discharge, whereas older dog’s eyes can be cloudy or opaque. 

  1. Take your dog to the vet:-

Your vet can accurately examine your dog’s age based on their physical exam or tests that evaluate the bones, joints, muscles, and organs. It’s the best way to get an accurate examination of your dog’s actual age.

One human year doesn’t equal seven dog years. It is also considered that dog age is one human year equals seven dog years. The origin of this formula is unclear, but it’s possible based on the average lifespan, which is about 10 years for a dog and 70 years for a human.

How to calculate your dog’s age in years?

If you’re looking to calculate your dog’s age in human years more accurately, you can use a new formula made by the researchers at the “University of California San Diego School of Medicine”. They showed that the DNA of humans and dogs changes over time looking at patterns called methyl groups in humans and Labrador Retrievers. They concluded that you can calculate your dog’s age to human years by multiplying the natural logarithm of the dog’s age by 16 and adding 31.

Their formula is: (human-age = 16ln(dog-age) + 31). 

The easy way to estimate your dog’s age, you can see this method as well; for small, medium, and large dogs under 100 lbs.

  • First-year of dog= 15 human years. 
  • The second year of dog= 9 human years.
  • Each additional year= 4-5 human years.
  • To determine the dog’s age through the table:
Dog SizeSmall dogs20 lbs or lessMedium dogs21-50 lbsLarge dogs51-100 lbsGiant dogs100+ lbs
Dog AgeAge in Human Years