Ohm's Law Calculator
Calculate voltage from current and resistance.
Enter Values
Calculation Result
How It Works
V = IR
Use consistent units or select the units you need.
How to use this calculator
What to enter
Enter or select the following as requested: Current; Current unit; Resistance; Resistance unit; Voltage result. Follow the units, valid ranges, examples, and options displayed beside each field.
What the result means
The electrical or energy result is calculated from the voltage, current, power, capacity, runtime, efficiency, or rate values entered. Check whether values are AC or DC, whether power factor and efficiency are included, and that voltage, current, energy, and capacity units are consistent.
When to use it
Use this for preliminary energy use, battery, solar, or electrical-load planning. Do not use a calculator result alone to size or install safety-critical electrical equipment; follow applicable codes and qualified professional guidance.