How do you determine your dog’s age in human years? Take how old they are and multiply by seven, right?
Well, not quite. Although this seems to be a standardised way of working it out, the result can be WAY off. This is because a dog grows more rapidly as a puppy than in his old age. Most breeds age at the same rate when they are young, but smaller breeds tend to age more slowly after five years old and can sometimes live twice as long as larger breeds. A one year old dog is approximately 15 years old in human years whilst a large breed dog aged 9 years old is actually 60 years old in human years.
Dogs age much faster than humans and have an average lifespan of 14 years, dependent upon a dog’s health, size, breed and lifestyle. Follow the steps below to work out how old your dog is in human years.
Work out how old your dog is in dog years. If you don’t know when your dog was born, check her teeth.
A puppy will have all of her baby teeth by eight weeks old and adult teeth by seven months old. A one to two year old dog will have minimal tartar build up whilst a dog up to five years old will start showing some yellowing of teeth. After five years old, some dogs may start getting tartar build up and dental diseases whilst a dog over ten may have greying fur, joint issues and eyesight problems.
Is your dog considered small, medium or large?
Small = less than 20lbs
Medium = 21lbs to 50lbs
Large = Over 50lbs
Dogs age at the same rate for the first five years of their life, but after this, larger breeds tend to age far faster than small breeds, which affects the calculation of your dog’s age in human years.
To calculate the approximate human age of your puppy, you’re going to need to do some basic maths as per the below formulas, which take into account the rapid growth during puppyhood and the decreased rate of aging as they get older.
- Puppies aged up to 2 months old = age in months x 2
For example, a 1 month old puppy is actually 2 months old in human years.
- Puppies aged 6 to 8 months = age in months x 1.5
For example, a 7 month old puppy is actually 10.5 months old in human years.
- Puppies aged 9 months to 2 years old = age in months x 1.25
For example, an 18 month old puppy is actually 22.5 months old in human years
- Dogs aged between 2 and 5 years old = (age in years – 2) x 4 +24.
For example, to work out the age in human years of a 5 year old dog, subtract 2 from 6, leaving 3. Now multiply that remaining 3 by 4 to equal 12. Now add 12 to 24. Your 5 year old dog is 36 years old in human years!
- Small dogs aged over 5 years old = (age in years -5) x4 + 36
- Medium dogs aged over 5 years old = (age in years -5) x5 + 36
- Large dogs aged over 5 years old = (age in years -5) x6 + 36
For example, an 8 year old medium dog would need to subtract 5 from 8, leaving 3. 3 multiplied by 5 is 15. 15 added to 36 is 51. Your 8 year old medium sized dog is 51 in human years.
Note that larger breeds have a ’growth spurt’ between the ages of 15 and 16 years old due to their larger bone structure, which can cause joint and health issues.