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Ohm's Law Calculator

Calculate Voltage (V), Current (I), Resistance (R), and Power (P) using Ohm's Law. Enter any two values to find the others.

Enter Any Two Values

Leave two fields blank — fill any two to solve for the rest.

Voltage V (volts)
Current I (amps)
Resistance R (ohms)
Power P (watts)
Results
All Values
PropertyValue

Ohm's Law

V = I × R | I = V/R | R = V/I | P = V×I = I²R = V²/R

Australian Electrical Standards

Australian mains supply: 230V AC, 50Hz (AS/NZS 3000 — "Wiring Rules"). Licensed electricians (A-grade) must perform all fixed electrical wiring in Australia under the Electricity Safety Act.

Ohm's Law Triangle

Cover the unknown: V = I×R | I = V/R | R = V/I. Power triangle: P = V×I = I²×R = V²/R