Ohm's Law Calculator

What Is a Ohm's Law Calculator?

Ohm's Law is the fundamental relationship in electronics linking voltage, current, and resistance: voltage equals current times resistance. Given any two of the three values, this calculator finds the third.

How to Use This Ohm's Law Calculator

1. Fill in any two of the three fields: Voltage (V), Current (A), and Resistance (Ω).
2. Leave the field you want to solve for blank.
3. Click Calculate to instantly find the missing value.

Formula

• V = I × R
• I = V / R
• R = V / I

Worked Example

A circuit has a 12 V source and 4 Ω of resistance. Leaving Current blank: Current = 12 / 4 = 3 A.