Ohm's Law Calculator

Calculate Voltage (V), Current (I), or Resistance (R) using Ohm's Law: V = I × R. Also calculates electrical power P = I × V.

Enter values above to calculate.

Ohm's Law Formula

V = I × R

Where:

  • V = voltage (Volts, V)
  • I = current (Amperes, A)
  • R = resistance (Ohms, Ω)

Power Formula

P = I × V = I² × R = V² / R

Where P = power (Watts, W).

Example

Problem: A 6 Ω resistor has 2 A of current flowing through it. Find the voltage and power.
Solution:
V = 2 × 6 = 12 V
P = 2 × 12 = 24 W

FAQ

What is Ohm's Law?

Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across those points and inversely proportional to the resistance.

What is electrical power?

Electrical power is the rate at which electrical energy is transferred. It's measured in Watts (W), where 1 Watt = 1 Joule per second.

Does Ohm's Law apply to all materials?

Ohm's Law applies to ohmic (linear) materials like most metals and resistors. Non-ohmic materials like diodes and transistors have non-linear relationships between voltage and current.

Last updated: 2026-08-08