Three phase power is a common method of alternating-current (ac) generation, transmission and distribution. It is the most common method used by electrical grids to transfer power worldwide. It is also used in large motors and other heavy loads. Three phase power can be measured by two watt-meters method. In this method we have two types of connections. They are star and delta connection of loads. In this electrical calculator, 3 phase power can be estimated using the star type connection.