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Ohm's Law Calculator

Solve for voltage, current, resistance, and power.

Enter any two values to calculate the others.

Understanding Ohm's Law

Ohm's Law is a fundamental principle in electronics and physics that describes the relationship between voltage, current, and resistance in an electrical circuit. It states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points.

The Core Formulas

The law is typically expressed in three primary forms, allowing you to solve for any one variable if you know the other two:

The Power Wheel

The relationship can be extended to include electrical power (P), measured in Watts. This is often visualized as the "Ohm's Law Wheel" or "Power Wheel," which provides 12 different formulas to solve for V, I, R, or P if you know any two values.

This calculator uses these formulas to automatically solve for the two unknown quantities when you provide any two known quantities.