Voltage Drop

Choose a voltage drop calculator for the information you have. Use Voltage Drop Calculator for current and conductor area in DC, single-phase or balanced three-phase circuits. Use Voltage Drop by Cable Length to compare areas or estimate the maximum route length for your target. Use Three-Phase Voltage Drop Calculator when you have electrical input kW or cable resistance and reactance. These three tools let you save up to three scenarios, restore inputs, download a comparison and create a link to your inputs. Review each tool’s assumptions: meeting a voltage-drop target does not establish conductor ampacity or installation compliance.

Choose by input and result

Use these direct routes to compare the available methods.

Voltage drop from current and conductor area — DC, single-phase or balanced three-phase; enter mm² or a listed AWG area.

AWG/kcmil voltage drop and size comparison — Compare 17 wire sizes or enter custom resistance in Ω/1000 ft.

Three-phase voltage drop from kW or cable impedance — Use electrical input kW or line current and resistance/reactance in Ω/km.

Cable distance and area — Estimate maximum route length for an entered voltage-drop target.

Check wire ampacity separately — Account for the model’s insulation, terminal, temperature and conductor-count limits.