How to use the DC Cable Size Calculator
The Formula
Undersized wire causes voltage drop and heat. This tool picks a conservative AWG from ampacity tables, then checks ~3% drop over your run length.
Practical Example
Inverters, motors, and lithium charging spikes may need the next size up. Follow local electrical code for final installs.
About DC Cable Size Calculator
DC wire sizing basics
Undersized wire causes voltage drop and heat. This tool picks a conservative AWG from ampacity tables, then checks ~3% drop over your run length.
When to go larger
Inverters, motors, and lithium charging spikes may need the next size up. Follow local electrical code for final installs.
Frequently asked questions
Q: One-way or round-trip length? A: Enter one-way distance; drop math uses round-trip resistance. Q: Copper only? A: Yes—aluminum needs larger gauge.