Ohm's Law Calculator
Solve for voltage, current, resistance or power.
Result
Results are estimates for general information only and are not professional advice.
Ohm's Law
Ohm's Law relates voltage, current and resistance: V = I × R. Enter any two values (leave the unknown as 0) and this calculator finds the third along with the power (P = V × I).
Frequently Asked Questions
What is the Ohm's Law Calculator?
Solve for voltage, current, resistance or power. It runs instantly in your browser and is completely free to use.
What do I need to enter to use the Ohm's Law Calculator?
The Ohm's Law Calculator asks for the following values (3): Voltage (V) — leave 0 to solve, Current (A) — leave 0 to solve, Resistance (Ω) — leave 0 to solve. Fill them in and the result appears immediately — the calculation runs on your own device, so nothing you type is sent to a server.
How accurate is the Ohm's Law Calculator?
The Ohm's Law Calculator uses standard, widely-accepted formulas, so its figures are reliable estimates for everyday planning. They are not a substitute for advice from a qualified professional.
Is the Ohm's Law Calculator free, and do I need an account?
Yes. The Ohm's Law Calculator — and every other calculator on Calculatis — is completely free, with no registration, no download and no limit on how often you use it.