Voltage Drop

Voltage Drop Calculator

Calculate voltage drop from current and total conductor resistance (VD = I × R).

Voltage Drop Percentage Calculator

Calculate voltage drop as a percentage of source voltage (%VD = (VD ÷ V) × 100).

Voltage Drop Distance Calculator

Calculate the maximum conductor run length for an allowable voltage drop (L = (VD × 1000) ÷ (I × R)).

Single-Phase Voltage Drop Calculator

Calculate single-phase voltage drop from current, conductor resistance, and one-way length (VD = 2 × I × R × L ÷ 1000).

Three-Phase Voltage Drop Calculator

Calculate three-phase voltage drop from current, conductor resistance, and one-way length (VD = √3 × I × R × L ÷ 1000).

Formula

Voltage Drop Formula

The voltage drop formula, its variables, and how single-phase and three-phase versions differ.

Example

Voltage Drop Examples

Worked, step-by-step examples calculating voltage drop, percentage drop, and maximum conductor length.

Guide

What Is Voltage Drop

Voltage drop explained: what causes it, why it matters, and how single-phase and three-phase circuits differ.