Pet Age Calculator

Do you know how old your pet is in human years?

This tool allows you to determine, roughly, what is the equivalence, in human years, of the actual age of a dog or a cat.

The calculator is based on a chart developed by Dr Fred L. Metzger that takes into account both the size of the pet and its actual age, in years.

Currently there is no rule that allows to convert the age of a pet in human years accurately. However, there are studies that allow an approximate calculation based on the real age, size and/or breed of the animal. These studies usually consider that pets do not age linearly. A dog, for example, usually ripens much faster in the first months of life:

  • The first 10 to 15 years of a human can be equivalent to 1 year of the life of a dog.
  • The next 3 to 8 years would be equivalent to another year.
  • From there, every 4 years would be equivalent to one year of a dog.

What seems clear is that the rule that considers 7 years of a human equivalent to 1 year of a dog is not really accurate.


  • Select your unit system: Metric (kg) or USA (lb).
  • Select the type of pet, its real age and its size.
  • The result will automatically be displayed below. The calculator indicates both the equivalent age of your pet and the stage of your life in which it is, that is, its degree of maturity.


Aging in dogs

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