Ohm's Law Calculator Ohm's Law Calculator Voltage (V) ? Voltage Formulas: V = I × R V = P ÷ I V = √(P × R) V mV kV Current (I) ? Current Formulas: I = V ÷ R I = P ÷ V I = √(P ÷ R) A mA µA Resistance (R) ? Resistance Formulas: R = V ÷ I R = V² ÷ P R = P ÷ I² Ω kΩ MΩ Power (P) ? Power Formulas: P = V × I P = I² × R P = V² ÷ R W mW kW Calculate Clear Enter any two values to calculate