About the Ohm’s Law Calculator
Find voltage, current, resistance and power with Ohm’s law. This tool is free, works in your browser and needs no sign-up.
How to use the Ohm’s Law Calculator
Choose what you want to find and enter the other two values.
Formula used
V = I × R. I = V ÷ R. R = V ÷ I. Power P = V × I.
Example
With Find Voltage (V), Voltage (volts) 12, Current (amps) 2, Resistance (ohms) 6, the calculator shows: Voltage = 12; Voltage (V) = 12; Current (A) = 2.
Frequently asked questions
Is the Ohm’s Law Calculator free to use?
Yes. It is completely free and you can use it as many times as you like.
How accurate is the Ohm’s Law Calculator?
The calculator uses standard formulas, so the maths is exact. Real life results can differ because of fees, taxes, rounding or personal factors, so treat the answer as an estimate.
Do you store the numbers I enter?
No. All calculations run in your browser. The values you type are not sent to our server.
Disclaimer: results are estimates for information only. They are not financial, medical or professional advice.