Voltage Drop Calculator

Approximate copper-wire voltage drop from current, one-way length, and AWG. Single-phase uses 2-wire path; three-phase uses √3.

Drop7.92 V
Percent6.60%
At load112.1 V

Vd ≈ 2 × I × R × L / 1000, R in Ω/kft. NEC often targets ≤3% branch, ≤5% feeder+branch. Aluminum is ~1.6× copper resistance.

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