Ohm's Law Calculator

    Calculate voltage, current, resistance & power

    Learn the formula

    Enter any 2 values to calculate the third. V = I × R

    Ohm's Law and Electrical Basics

    Ohm's Law states that voltage (V) equals current (I) times resistance (R): V = I × R. This simple relationship governs most DC circuits and is the first equation every electronics student learns. This calculator solves for any one of the three variables when you know the other two, and also computes power (P = V × I) as a bonus output.

    Applications range from designing resistor networks and LED circuits to diagnosing faults in home electrical systems. The calculator uses SI units by default (volts, amperes, ohms, watts) but you can convert inputs as needed. All calculations are instantaneous and client-side.

    Frequently Asked Questions