Ohm's Law Calculator

About This Calculator

This Ohm's Law calculator helps you quickly compute key parameters for your electronic designs. Whether you're a professional engineer or a hobbyist, this tool provides accurate results based on industry-standard formulas.

Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points. The relationship is expressed as V = I × R, where V is voltage in volts, I is current in amperes, and R is resistance in ohms.

How to Use

Enter any two known values in the input fields above. The calculator will automatically compute the remaining values in real time. All calculations are performed in your browser — no data is sent to any server.

For example: enter 12V for voltage and 0.5A for current, and the calculator will instantly show you the resistance (24Ω) and power (6W).

Formulas

V = I × R — Voltage equals current multiplied by resistance

I = V ÷ R — Current equals voltage divided by resistance

R = V ÷ I — Resistance equals voltage divided by current

P = V × I — Power equals voltage multiplied by current