Ohm's Law Calculator

Voltage, current, resistance and power from any two values.

A
Ω
Voltage
20V
Power
40W
Show the working
  1. 1V = I × R = 2 × 10 = 20 V
Formula
V = I × R, P = V × I

How it works

Ohm's law relates voltage, current and resistance. Give any two and the third — plus the power — follows.

Example

2 A through 10 Ω needs 20 V and dissipates 40 W.

About the Ohm's Law Calculator

Voltage, current, resistance and power from any two values. It sits in the Physics & Engineering section of NWS Calc, a free collection of calculators that run entirely in your browser. There is no signup, no paywall and no tracking — open the page, enter your numbers, get an answer.

Frequently asked questions

Is the Ohm's Law Calculator free to use?
Yes. Every calculator on NWS Calc is completely free, with no signup, no usage limits and no ads.
Does my data leave my device?
No. The Ohm's Law Calculator runs entirely in your browser using JavaScript. Nothing you type is uploaded, logged or stored on a server.
Can I use the Ohm's Law Calculator on my phone?
Yes. The page is fully responsive and works in any modern mobile or desktop browser — there is nothing to install.
What else is in Physics & Engineering?
Motion, force, energy, electricity and wave calculations. You can browse the full Physics & Engineering category for related calculators.

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