Ignition Coil Wiring Calculator

ignition type
cylinder count
max. RPM
max. set Dwell
current draw per coil
wire size unit
calculate required wire gauge



Ignition Type
sequential – every coil fires seperately (every second engine cycle)
wasted spark – coils wired in pairs (firing every engine cycle)
This calculator is designed for direct coil on plugs (number of coils = number of cylinders). If you are using real wasted spark coils (one coil firing two cylinders), set to wasted spark and enter half of actual current draw.

Cylinder Count
number of cylinders

max. RPM
maximum RPM your engine will be running at

max. set Dwell
maximum dwell you will be using – NOT the maximum allowed coil dwell

current draw per coil
maximum current your coil is drawing at your max. set dwell – NOT the maximum current your coil can draw.
If you dont know the current draw of your coil at your chosen dwell, it’s easy to calculate, as current rises linearly while charging:
current draw = max. current x ( set dwell / max. dwell )


This calculator calculates the minimum required wire gauge for your ignition coil power supply. The given results allow for 2.2% voltage drop assuming a total power supply wire length of 3 meters.

This calculator is for informational purposes only. We do not take any responsibility for any damages or injuries.