Ohm's Law Calculator for Electronics/Electrical Tools. And For Electrical Engineering Education. Features. Ohm's Law Calculator. (Power ( W. ), Voltage ( V. ), Current ( A. ), Resistance ( Ω. ). 12 Ohm's Law formula ( P = EI, E = IR, I = E/R, R = E/I and other). Show Calculate Result on Graphics Display UI and Text. Free Version with Ad. Full Android Source Code.