Ohm's Law Calculator
Calculate voltage, current, resistance, and power using Ohm's Law relationships
About this calculator
An Ohm's Law Calculator is an essential tool for electrical engineers, technicians, and students that instantly computes voltage (V), current (I), resistance (R), and power (P) using the fundamental relationships V=IR, P=VI, P=I²R, and P=V²/R. This calculator eliminates manual calculations and reduces errors when analyzing electrical circuits, designing systems, or troubleshooting electrical problems. Whether you're working on circuit analysis, component selection, or power calculations, this tool provides accurate results for any two known values, making electrical calculations faster and more reliable.
How to use
Enter any two known electrical values (voltage, current, resistance, or power) into the corresponding input fields. The calculator will automatically compute the remaining two unknown values using Ohm's Law relationships. Simply input your measurements in the appropriate units, and the tool will instantly display all four electrical parameters with precise calculations.
Frequently asked questions
What is Ohm's Law and why is it important?
Ohm's Law states that voltage equals current times resistance (V=IR). It's fundamental for understanding electrical circuits, power consumption, and component behavior in electronic systems.
What units should I use in the calculator?
Use standard electrical units: volts (V) for voltage, amperes (A) for current, ohms (Ω) for resistance, and watts (W) for power calculations.
Can I calculate power consumption for household appliances?
Yes, enter the appliance's voltage and current ratings to calculate power consumption, or use voltage and resistance values to determine energy usage.