Electrical calculator

Ohm's Law Calculator

Calculate voltage, current, or resistance using Ohm's law. Enter any two values to solve for the third.

Voltage V = I × R

Current I = V ÷ R

i Ohm's law relates voltage (V), current (I), and resistance (R). Power can also be derived as P = V × I.

Instant result

Result

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Enter values to calculate.

Inputs—

Mode—

Formula—

How to use

Follow these steps for a clear answer.

Select whether you want voltage, current, or resistance.

Provide the two known quantities in volts, amps, or ohms.

The calculator solves Ohm's law instantly in your browser.

Common configurations with formula and result.

2 A through 12 Ω

2 × 12

24 V

120 V across 60 Ω

120 ÷ 60

2 A

9 V at 0.03 A

9 ÷ 0.03

300 Ω

Solve for	Known values	Formula	Result
Voltage	2 A, 12 Ω	V = I × R	24 V
Current	120 V, 60 Ω	I = V ÷ R	2 A
Resistance	9 V, 0.03 A	R = V ÷ I	300 Ω
Voltage	0.5 A, 220 Ω	V = I × R	110 V

i Enter positive values. Results are shown with up to three decimal places when needed.

Key distinctions behind the calculation.

What is Ohm's law?

Ohm's law states that voltage equals current multiplied by resistance (V = I × R).

Can I calculate power with this tool?

Yes. Once voltage and current are known, power in watts is P = V × I.

What units should I use?

Use volts (V), amps (A), and ohms (Ω). Keep units consistent for accurate results.