Electrical Capacity Calculator
Calculate your electrical system's capacity to support your amplifiers
Alternator(s)
Use your alternator's rated output, not max output
Batteries
System Settings
Target Power (Optional)
Enter your amplifier's RMS power to compare it with the entered electrical output
Electrical Capacity
Big 3 Wiring
Size wiring for actual current and run length using the Wire Calculator and consult your equipment manuals. The Big 3 wiring paths are:
- Alternator positive → Battery positive
- Battery negative → Chassis ground
- Engine block → Chassis ground
MAKING SENSE OF IT
Continuous estimates power from the entered alternator output at a fixed voltage. Actual output varies with operating conditions and vehicle loads.
Burst estimates battery current from capacity and a C-rate at fixed voltage; it does not establish a duration or account for voltage sag and battery condition.
Headroom compares the entered alternator output with the calculated target draw; it does not guarantee voltage stability.