Ohm's Law Calculator
Calculate voltage, current, or resistance using Ohm's Law
About this calculator
Ohm's Law Calculator is an essential tool for electrical calculations that helps determine voltage, current, or resistance in electrical circuits. Based on the fundamental relationship V = I × R (Voltage equals Current times Resistance), this calculator simplifies complex electrical computations for students, engineers, and technicians. Whether you're designing circuits, troubleshooting electrical problems, or learning electronics fundamentals, this calculator provides instant, accurate results for any two known values while automatically calculating the unknown third parameter.
How to use
Enter any two known values from voltage (V), current (I), or resistance (R) into the appropriate input fields. The calculator will automatically compute the missing third value using Ohm's Law formula. Select appropriate units (volts, amperes, ohms) and click calculate to get instant results with precise measurements for your electrical calculations.
Frequently asked questions
What is Ohm's Law and how does it work?
Ohm's Law states that voltage equals current multiplied by resistance (V = I × R). It describes the fundamental relationship between these three electrical quantities in any circuit.
What units does the Ohm's Law calculator use?
The calculator uses volts (V) for voltage, amperes (A) for current, and ohms (Ω) for resistance. Most calculators also support common prefixes like kilo, milli, and micro.
Can I calculate power using Ohm's Law?
Yes, power can be calculated using P = V × I, P = V²/R, or P = I² × R. Many Ohm's Law calculators include power calculations alongside voltage, current, and resistance.