Ohm's Law Calculators | Car Audio Electrical Tools | Garage Audio
Electrical Calculators for Car Audio
Quick Ohm's Law calculators for car audio and 12V electrical systems. Calculate voltage, current, power, or resistance—just select what you know, enter the values, and get instant results. Built for Aussie installers, DIYers, and audio enthusiasts.
Key Terms
E = Voltage (Volts) — The electrical pressure pushing current through a circuit
I = Current (Amps) — The flow of electrons through a circuit
P = Power (Watts) — The rate of energy transfer
R = Resistance (Ohms) — Opposition to current flow
Voltage Calculator
Voltage is the electrical pressure between two points in a circuit. Automotive systems run on 12V DC, powering everything from your ignition to your stereo and lights. Use this calculator to find voltage when you know other values.
Current Calculator
Current is the flow of electrons through a circuit, measured in Amps. Electrons flow from negative to positive (think of your car battery terminals). Use this to calculate how much current your system draws.
Power Calculator
Power is the rate of energy transfer, measured in Watts. If you're running a 500W amp, it's drawing 500 watts of electricity every second it's on. Use this to calculate power consumption of your audio gear.
Resistance / Impedance Calculator
Resistance (or impedance) opposes the flow of electrons in a circuit, measured in Ohms. Copper has low resistance (great conductor), rubber has high resistance (great insulator). Speaker impedance is critical for matching amps correctly.