Southwire Voltage Drop

Southwire Company

About this app

Southwire's voltage drop calculator will help you determine the proper wire size for an electrical circuit based on the voltage drop and current carrying capacity of an electrical circuit. Determines wire size to meet specific voltage drop limits or calculates voltage drop for a specific conductor run. When sizing conductors, calculations limits wire size to voltage drop and NEC ampacity. Southwire's Voltage Drop Calculator is designed for applications using AWG and KCMIL sizes only.

Ratings and reviews

Very useful app! Very easy to explain and show an non-electrically inclined person why they have voltage issues under full load with long wire runs of insufficient gauge. Only suggestion would be, add split phase (dual phase) selections, as most of North America residential and small commercial power is 240v split phase, not just single phase 120v or three phase as is available in the app now.

Just checked it. It has indeed been fixed and works great again. Thank you for the update! As a plant electrician running around constantly this is a must have app for anyone running work or even apprentices trying to learn and get better at doing electrical.

Works well for the awg listed, but it doesn't go small enough. Should go down to 18 awg at least. Also, it would be nice to have a separate table showing max amps on a specific awg wire, so I know I can't use 12 awg at all, if I need 40 amps; It just doesn't work.

What’s new

Behind the scenes updates.