Age Calculator for Dogs & Cats: Your Pet's Age in Human Years

What is a ‘Pet Year’?

Dogs and cats age more rapidly than humans. At one time or another we’ve all heard the expression ‘dog years’, but most of us are unaware of how the relative age and weight of our pets is calculated by veterinarians and others in the pet health field.

The Pets Plus Us age calculator provides an invaluable tool for pet owners to determine their furry companions' equivalent age in human years. This chart empowers pet owners to make better decisions regarding their pet's health and care by providing them with a clear understanding of their pet's aging process. By shedding light on the relative age and weight of pets, the age calculator also serves as a valuable resource for those working in the pet health field, ultimately promoting the well-being and longevity of our beloved animal companions.

For cats, one human year is roughly equal to 6 - 7 cat years.

For dogs, it’s slightly more complicated, as size and weight also have an impact. Generally, the heavier and larger the dog, the more swiftly they age.

Our Dog and Cat Age Calculator

To help you determine the relative age of your pet, we’ve created this Cat & Dog Age Calculator chart for quick reference. This pet age chart will help you better understand your pet's aging process and make informed decisions regarding their health and care.


Weight (lb)


Weight (lb)

Age (years) 0-20 0-20 20-50 50-90 >90
1 7 7 7 8 9
2 13 13 14 16 18
3 20 20 21 24 26
4 26 26 27 31 34
5 33 33 34 38 41
6 40 40 42 45 49
7 44 44 47 50 56
8 48 48 51 55 64
9 52 52 56 61 71
10 56 56 60 66 78
11 60 60 65 72 86
12 64 64 69 77 93
13 68 68 74 82 101
14 72 72 78 88 108
15 76 76 83 93 115
16 80 80 87 99 123
17 84 84 92 104 131
18 88 88 96 109 139
19 92 92 101 115 -
20 96 96 105 120 -

Table courtesy of Fred L. Metzger, DVM, DABVP

Colour key

  • Adult
  • Senior
  • Geriatric

Pets and aging

Why does it matter how old our pets are? It’s important to keep in mind that as our pets age, we need to make changes in their nutrition, exercise habits, and even their sleep patterns to help them stay healthy and happy.

Dogs and cats age more rapidly than humans, with their lifespans significantly shorter in comparison. While the concept of "dog years" is familiar to many, the majority remain unaware of the precise methods employed by veterinarians and experts in the pet health field to calculate the relative age and weight of our beloved pets.

As pets age they also become more prone to disease and along with this, more likely to develop common conditions associated with their species and breed. It follows that as a responsible pet owner, when you’re knowledgeable about your dog or cat’s breed and age, the easier it is to prevent and watch for symptoms of decline before they become serious.

Not sure of your pet’s age?

If you adopted or rescued your pet and aren’t exactly sure of their real age, veterinary professionals have a few ways they can use to estimate this.  As always, you should consider consulting your veterinarian and clinic staff for help with calculating your pet’s age, their predisposition to certain diseases, and for healthy aging care and tips for your pet.

Pet health insurance offers numerous benefits to pet owners, providing peace of mind and financial protection. It can help ensure that pet owners can afford quality veterinary care without hesitation or compromise. In case of unexpected illnesses, accidents, or chronic conditions, pet insurance can help cover veterinary expenses, including diagnostic tests, surgeries, medications, and treatments. This enables pet owners to make timely decisions based on their pet's best interests rather than financial constraints. 

Insuring older pets

Pet insurance premiums are calculated using 4 factors: species, age, breed and postal code. Like with humans, as our pets age they are more at risk for developing certain conditions. Pet insurance coverage is available and still very viable for aging and senior pets, but it’s always better to insure them earlier to ensure they can get the most comprehensive coverage, with the lowest possible premiums and deductibles.