Note: This calculator uses a method developed by Monsieur LeBeau which is more accurate than the common seven dog years per one human years estimate. After one year your dog or puppy will have the age of a fifteen year old person. At two years, the pet will have an equivalent age of twenty four. For the years between two and fourteen, the dog will age at a rate of four human years. After fourteen, the canine will age at a rate of two and a half human years.