Fill in any two values and leave the third blank, then click Calculate.
Ohm’s Law is the foundation of basic electrical calculations, relating voltage, current, and resistance. This calculator solves for whichever value you’re missing.
How to Use This Calculator
Enter any two of the three values (Voltage, Current, Resistance) and leave the third field empty, then click Calculate to solve for it.
Formula
V = I × R, which can be rearranged to I = V ÷ R or R = V ÷ I.
Frequently Asked Questions
What is Ohm’s Law?
Ohm’s Law states that voltage equals current multiplied by resistance (V = IR), describing the relationship between these three electrical quantities.
What units does this calculator use?
Volts (V) for voltage, Amps (A) for current, and Ohms (Ω) for resistance.
Does Ohm’s Law apply to AC circuits?
It applies directly to simple resistive circuits. AC circuits with inductance or capacitance require impedance calculations instead of plain resistance.