Calculators
Ohm's Law Calculator
Solve for voltage, current, resistance, or power with Ohm's law locally in your browser.
Choose what to solve for, then enter the other two values using consistent electrical units (volts, amperes, ohms, and watts). Calculations run locally in your browser; your values are not uploaded or stored.
Solve voltage, current, resistance, and power without uploading anything.
Choose whether to solve for voltage, current, resistance, or power, then enter the other two values with consistent electrical units. The calculator applies voltage = current x resistance, current = voltage / resistance, resistance = voltage / current, or power = voltage x current and shows the worked formula. Everything runs locally in your browser, so your values are not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
Which formulas does the Ohms law calculator use?
It uses voltage = current x resistance, current = voltage / resistance, resistance = voltage / current, and power = voltage x current. For example, 2 amperes through 6 ohms gives 12 volts, and 12 volts at 2 amperes gives 24 watts.
Which inputs are accepted?
Enter values of zero or greater up to 1,000,000,000,000. Resistance must be greater than zero when solving for current, and current must be greater than zero when solving for resistance. Missing or non-numeric entries show a clear error instead of a result.
Which units should I use?
Use volts with amperes, ohms, and watts. The answer is reported in the matching unit: volts (V), amperes (A), ohms, or watts (W).
Do my values stay private?
Yes. The calculation and copy action run locally in your browser. CodeASystem does not upload or store the values you enter.