Free Solar Wiring Tool · 2026

Solar Cable & Wire Sizing Calculator

Calculate DC and AC cable gauge for PV strings, battery-to-inverter runs and AC output. Get AWG, mm², voltage drop, ampacity and NEC 690 compliance.

Run Settings
Used when Custom selected above
Leave blank if entering amps directly
Results
Recommended Wire Gauge
Configure run and click Calculate
Metric Equivalent
mm²
Ampacity (derated)
A

Resistivity: Cu 1.724×10⁻⁸ Ω·m, Al 2.82×10⁻⁸ Ω·m at 20°C. NEC ampacity based on 75°C column, copper in conduit.
NEC 690.8 requires ×1.25 for continuous PV current. Always verify with local electrical code.
Built by DoCrack.me · Free to use · No signup required