Here's a general idea:
* First year: Roughly equivalent to 15 human years
* Second year: Roughly equivalent to 9 human years
* After that: Each dog year is roughly equivalent to 4-5 human years
So, a 5 year old dog is roughly equivalent to 36-40 human years old.
Important Note: These are just rough estimates. For a more accurate assessment, consult your veterinarian. They can factor in your dog's breed, size, and overall health to give you a better idea of their age in human years.