When it comes to determine the solar inverter size, the solar installers will take 3 major factors into consideration: the size of your solar array, your geography, and site-specific conditions. The size of your solar inverter can be larger or smaller than the DC rating of your solar array, to a certain extent. The array-to-inverter ratio of a solar panel system is the DC rating of your solar array divided by the maximum AC output of your inverter. The majority of installations will have a ratio between 1.15 to 1.25; solar inverter manufacturers and solar power system designers typically don’t recommend a ratio higher than 1.55.