Many of us grew up being taught that one dog year equals seven human years. So, if your dog is five years old, he is the equivalent of a 35-year-old human. This theory is still extremely popular, but in truth, it’s far from accurate. A dog’s human age is influenced by factors such as size, and there are even differences between different species of animals! We took a look at the real ages of animals.
How old is my pet?
Are you curious about how old your pet may be in human years? Other than satisfying a mild curiosity, an idea of an animal’s age can help you to understand behaviours and what you can expect of him. You can also make adjustments to some things, such as food and healthcare, as natural changes occur throughout the pet’s different life phases.
There is a number of pet age calculating sites available on the internet, which shows that different animals age at different rates, and some animals’ rate of aging changes as they grow older too. A rabbit of six months is the human equivalent of 16 years, yet at one year he will only be the equivalent of 20 human years. At three years, this rabbit will be 36 human years. Let’s take a wildlife example: in the first year, a ferret will age 22 human years, but as he gets older, he will age slower – at three years of age, he will be 42 years old, not the human equivalent of 66 years (3 x 22).
Calculating an animal’s age is not an exact science – there is still a lot of speculation on this subject for different pets, and so it is a rough estimate.
In the case of dogs, a large dog ages at an accelerated pace according to an evolutionary biologist in Germany, Cornelia Kraus. At one year, a medium-sized dog is about 15 human years. At year two, add nine years, and after that, for each actual year the age increases by five years for the dog. Small, medium and large dogs age differently. The smaller the dog, the slower he will age compared to a very large dog. Cats and small dogs are considered mature at seven years of age. The oldest recorded age of a dog is 29 years.
For a cat, at the end of the first two years, she is about 25 years old in human years, and after this add four years on each year – so a cat of seven years is about 45 years old. Not a reliable method, but it gives you a good idea. The oldest known cat lived for 34 years, which equals 153 years old!
Life expectancy
Have you ever wanted to know what a specific pet’s life expectancy is? This information is very helpful to someone who is deciding on purchasing a particular pet. An owner will know how many years of responsibility they will be taking on for the good care of this animal. Lifespan is always affected by care, diet, trauma experienced, living conditions (are the conditions closest to the natural habitat?), exposure to stress, and the pet’s ability to retreat and rest well. Disease and genetics also play a large role. Inbreeding can shorten lifespan too.
Having said all that, let’s have a look at some numbers. As mentioned before, this is not an exact science, but it will give you a good idea of how old your pets really are.
Animal Medium dog
Age 1
Human year equivalent 15
Life expectancy in human years 9-15
Animal Dog (small, medium, large)
Age 8
Human year equivalent 48 (small), 51 (medium), 55 (large)
Animal Cat
Age 2
Human year equivalent 25
Life expectancy in human years 16-21
Animal Rat
Age 1
Human year equivalent 27
Life expectancy in human years 2
Animal Guinea pig
Age 1
Human year equivalent 10
Life expectancy in human years 4-8
Animal Pigeon
Age 1
Human year equivalent 7
Life expectancy in human years On average 3-5 years
Animal Duck
Age 1
Human year equivalent 4
Life expectancy in human years 5-10 depending on species
Animal Chicken
Age 1
Human year equivalent 5
Life expectancy in human years 5-10 depending on species
Animal Parakeet/budgie
Age 1
Human year equivalent 5
Life expectancy in human years 5-15
Animal Hamster
Age 6 months
Human year equivalent 34
Age 1
Human year equivalent 58
Life expectancy in human years 3-4
Animal Mouse
Age 6 months
Human year equivalent 34
Age 1
Human year equivalent 58
Age 3
Human year equivalent 100
Life expectancy in human years 2-3
Animal Horse
Age 1
Human year equivalent 3
Age 5
Human year equivalent 15
Life expectancy in human years 40
Animal Rabbit
Age 6 months
Human year equivalent 16
Age 1
Human year equivalent 20
Life expectancy in human years 8-12 or 14-16, depending on species
Animal Finch, canary, sparrow
Age 1
Human year equivalent 18
Age 3
Human year equivalent 35
Life expectancy in human years 15
Animal Snake (boa/python)
Age 1
Human year equivalent 18
Age 3
Human year equivalent 30
Age 5
Human year equivalent 42
Life expectancy in human years 15-20
How do wild animals compare?
A few wild animals are also shown below. There is a difference in the aging process when an animal is living in captivity or in the wild. Natural predators and untreated diseases occur in the wild and the availability of food is not always consistent. Animals in captivity in a responsible institution are fed regularly, given health checks, and although there is a certain level of stress related to being in captivity, these animals live longer lives.
Animal Ferret
Age 6 months
Human year equivalent 18
Age 1
Human year equivalent 22
Life expectancy in human years 8-12
Animal Hippo
Age 1
Human year equivalent 1.78
Life expectancy in human years 36
Animal Monkey
Age 1
Human year equivalent 3.2
Life expectancy in human years 10-50 depending on species
Animal Lion
Age 1
Human year equivalent 2.29
Life expectancy in human years 20-25 in captivity; 10-16 in the wild
Animal Tortoise
Age 1
Human year equivalent 12
Age 5
Human year equivalent 52
Life expectancy in human years 80
Animal Gecko
Age 1
Human year equivalent 16
Age 5
Human year equivalent 40
Life expectancy in human years 10-20
