Ohm's Law Calculator

Calculate Voltage (V), Current (I), Resistance (R), or Power (P) given any two knowns.

JavaScript Required: This interactive calculator requires JavaScript. The formula is V = I × R, and P = V × I.

Voltage (Volts) Current (Amps) Resistance (Ohms)

Enter any two values.

Theory

Ohm's law defines the relationship between voltage, current, and resistance in an ideal conductor. Power dissipation is an emergent property of this relationship.