Wire & solar calculator.
What wire for 60 A over 12 feet? Which controller for four panels? A free, honest calculator that knows about voltage drop, hot engine bays and exhaust runs.
What it checks
Wire is more than amps and feet.
- Voltage drop over the full round trip, so 12 V runs do not starve your loads.
- Current capacity after derating for heat and for bundled wires.
- Engine bay and exhaust: higher heat ratings, high-temperature loom and a warning to re-route.
- The right fuse: protects the wire, not just the load.
- Solar strings: cold-weather voltage against the controller limit, plus PV and battery wire and fuses.
Free app
Coming soon
Wire & Sun for your phone
The same calculator as a free app that works offline in the van, at the shop or on the roof.
Estimates for planning, not a design. Final sizing is confirmed in the install guide for your kit, and every system should be reviewed by a licensed electrician before you install it.
Rather have it all in one box?
Our kits ship with every wire cut to the right size and a plan that shows where each one goes.