Ohm's Law Calculator

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Calculates voltage, current, or resistance in an electrical circuit using Ohm's Law (V=IR).

How To Use

How to use this calculator

Start with your values, or try a preset.

Step 1

Enter Voltage (V), Current (I), Resistance (R), and Calculate in the units shown.

Step 2

Read Resistance (R), Current (I), and Voltage (V) in the results panel. Results update as you change the inputs.

Step 3

Choose a preset to load an example, then adjust the values for your situation.

Worked Examples

See the inputs and their calculated results.

Voltage (V): 12 V; Current (I): 2 A; Resistance (R): 6 Ω; Calculate: Resistance (R)

Resistance (R): 6 Ω; Current (I): 2 A; Voltage (V): 12 V

Voltage (V): 12 V; Current (I): 2 A; Resistance (R): 6 Ω; Calculate: Voltage (V)

Resistance (R): 6 Ω; Current (I): 2 A; Voltage (V): 12 V

Voltage (V): 12 V; Current (I): 2 A; Resistance (R): 6 Ω; Calculate: Current (I)

Resistance (R): 6 Ω; Current (I): 2 A; Voltage (V): 12 V

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