Alternator Output Calculator

Calculate electrical load and determine alternator requirements for your vehicle.

Current Alternator

Electrical Loads (Watts)

Typical: 110-150W
Typical: 40-80W
Typical: 100-200W
Typical: 200-400W
RMS power draw

Common Load Reference

ComponentTypical WattsAmps @12V
Halogen Headlights110-150W9-13A
LED Headlights40-60W3-5A
Electric Fan (single)150-200W13-17A
Fuel Pump60-120W5-10A
1000W Audio Amp~1200W~100A