How to use Ohm's Law Calculator
Enter the required values, choose the relevant options, and read the instant result. Use Reset to restore the default example and Copy result when you need to save the output.
Free online calculator
Ohm's Law Calculator
Solve voltage, current, resistance, and power.
Electrical
Ohm's Law Calculator
Solve voltage, current, resistance, and power.
Web app
Ohm's Law Calculator
Runs locally. Works on mobile and desktop.
Result
Table of contents
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About this calculator
Solve voltage, current, resistance, and power. The calculation runs entirely in your browser, so the page stays fast and does not require uploads.
Good checks
Review units before comparing results, keep inputs positive when the formula requires it, and round only after the final answer when precision matters.