DC Cable Sizing Tool
This online cable size calculator tool makes it easy to establish the correct size of cables for any DC power system.
DC Wire Sizing Calculator - Round your results up to the next cable size
Cable sizes: 'Free Air cables' can carry the following Amps (cables in conduit or insulated walls will reduce the Amps you can put through the cable). The table below shows our recommended max amps to put though the DC solar and battery cable sizes we supply in free Air. If installing in insulated walls or ducting you will need to reduce the current carrying capacity accordingly. Consult with a qualified electrican if you are unsure of how to do this. The 6mm and 10mm refer to solar cable. The remaining sizes refer to battery/welding cable. You can download the datasheet for the cable here.
Cable Size |
Max Amps in Free Air |
6mm² |
70A |
10mm² |
98A |
16mm² |
135A rated for 5mins @ 100% Duty |
25mm² |
180A rated for 5mins @ 100% Duty |
35mm² |
225A rated for 5mins @ 100% Duty |
50mm² |
285A rated for 5mins @ 100% Duty |
70mm² |
355A rated for 5mins @ 100% Duty |
95mm² |
430A rated for 5mins @ 100% Duty |
120mm² |
500A rated for 5mins @ 100% Duty cycle, 850Amps at 35% duty cycle |
The information contained within this table is for guidance only and is subject to change without notice or liability. All the information is provided in good faith and is believed to be correct at the time of publication. When selecting cable accessories, please note that actual cable dimensions may vary due to manufacturing tolerances.