AWG, mm², and voltage drop
Electrical, EV & Solar
Copper and aluminum wire size, NEC voltage-drop checks, end-of-line voltage, and I²R loss for branch circuits and feeders.
Master calculators
Preset pages
50 Amp EV Charger Wire Size at 50, 75, and 100 Feet
A continuous 50 A, 240 V charger. The table repeats 50, 75, and 100 ft runs.
100 Amp Subpanel Feeder: Copper vs Aluminum
A 100 A, 240 V feeder at 80 ft, with copper and aluminum side by side.
30 Amp RV Outlet Wire Gauge and Voltage Drop
A 120 V, 30 A TT-30 style outlet where voltage drop shows up quickly.
200 Amp Main Service Entrance Wire Size
A 200 A service lateral where ampacity, not voltage drop, usually governs.
240 V Mini-Split Heat Pump Wire Gauge
A 25 A heat pump on 240 V, 60 ft from the panel, with the 125 percent ampacity check on.
60 Amp Detached Garage Subpanel Wire Size
An 80 ft feeder to a detached garage subpanel at 60 A.
20 Amp Well Pump Wire Size at 150 Feet
A long 150 ft well branch where drop, not the 20 A breaker, picks the wire.
15 Amp Lighting Run Voltage Drop at 100 Feet
A 100 ft, 120 V lighting circuit at 15 A and a 3 percent limit.
40 Amp Electric Range Wire Size at 40 Feet
A short 40 ft, 40 A range circuit where ampacity usually wins.
480 V Three-Phase 100 Amp Shop Feeder
A 100 A, 480 V, three-phase feeder, 120 ft, copper in EMT.