Voltage Drop Calculator.

Voltage Drop Calculator provides fast, accurate electrical calculations for electricians, engineers, and contractors. Calculate voltage drop and wire sizing using NEC or IEC standards, with support for AWG, kcmil, and mm² conductors, copper or aluminum wiring, single- and three-phase systems, power factor, continuous loads, grouping, and ambient temperature corrections.

Use the reverse wire size calculator to find the optimal conductor for a target voltage drop. Review ampacity, derating, load voltage, and compliance results, convert wire sizes, generate shareable PDF reports, and access electrical formula cards. Available in English, Spanish, French, German, Italian, Dutch, Portuguese, and Chinese.