Ohm's Law Calculator

Calculate Voltage, Current, and Resistance Online for Free

Enter any two of voltage (V), current (I), and resistance (R), and the calculator will automatically determine the remaining value along with power (W). Includes a circuit diagram and Ohm's Law wheel for intuitive understanding.

Select Calculation Mode

Voltage V
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Current I
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Resistance R
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Power P
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Circuit Diagram

V R I

Ohm's Law Wheel

V = I x R P = V x I V I x R P / I √(P x R) I V / R P / V √(P / R) R V / I V² / P P / I² P V x I I² x R V² / R

Basic Formulas

V = I × RVoltage = Current × Resistance
I = V / RCurrent = Voltage / Resistance
R = V / IResistance = Voltage / Current
P = V × IPower = Voltage × Current

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