Calculate voltage, current, resistance, and power using Ohm's Law.
The Voltage Calculator solves Ohm's Law and power equations for you — enter any two known values among voltage, current, resistance, and power, and it calculates the rest. It's free and runs entirely in your browser, making it a quick reference for electronics hobbyists, students, and engineers who need a fast check without pulling out a formula sheet.
Made for everyone. Typical uses:
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