We all use many units such as length, weight, temperature, time, speed in some way. As the system of units, we prefer the system of SI, which is accepted by almost all countries. The International Unit System was adopted at the 11th General Conference on Weights and Measures in 1960 in order to eliminate unit confusion among countries. Meters are used for length, kilograms for weight and seconds as time units. Undoubtedly, you cannot keep all these units and translations between units in mind. Fortunately, you can do the human age conversions of dog age and cat age with many units we use. You can perform all these calculations on both computers and smartphones.