A dog's age can be estimated by its overall body development, maturity and aging signs. It's calculated in a ratio to human calendar year, and different breeds have different ratios. Since there are numerous factors that affect a dog's life span, the following table is only average data for reference.
Age Conversion Tips
Different sized dogs have different age conversion methods. Generally, small dogs live longer than large dogs, so body size needs to be considered when calculating age. The chart above provides general reference values, but your dog's actual "human age" may vary depending on health conditions, breed characteristics and other factors.