Conductor sizing
Voltage drop calculator
Estimate voltage drop, percent drop, and end voltage — copper or aluminum, single- or three-phase — sized to NEC 3% / 5% guidance.
Voltage drop
—Enter a run to estimate voltage drop.
| Voltage drop | — |
|---|---|
| Percent drop | — |
| Voltage at load | — |
| Resistance used | — |
NEC 3% branch NEC 5% total
Estimate only — not a substitute for a licensed electrician.
Based on NEC Ch.9 Table 8 DC resistance. Does not model ampacity, temperature
derating, power factor, or continuous-load factors. Verify against the current NEC and
your local code / AHJ.