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.

What’s New

Version 3.1.3

New widget to display last calculation results.

Ratings and Reviews

4.4 out of 5
681 Ratings

681 Ratings

mchcfamily ,


calculator works as expected.

dqyrireplingfd ,


The company tech support group has always had the answers.
Any and every question I’ve posed has alway been answered with background or historical grounding.

1MidwestMadMan ,

Choice Between AWG and Metric wire Gauge

Why does this app give a choice of Metric vs. Imperial? When I chose metric in the inputs and go to the next screen for voltage drop calculation there is no option but to use AWG and no option for metric cable size e.g. 2.5, 4, 6, 10, 16, 25, 35, 40, 50, 70, 95, 120, 150, 185, 240, 300, 400 mm2 size conductors. I am currently working British Standard regulations and really though I had something useful with this app for a min. Guess not.

Developer Response ,

We're sorry to hear Southwire's Voltage Drop Calculator did not meet your needs. Metric vs. Imperial refers to the cable length, not the cable size. We understand how that could be confusing, so we're going to make some changes to the app store description and within the app itself to make this easier to discern. Southwire's Voltage Drop Calculator is designed for applications using AWG and KCMIL sizes only.

App Privacy

The developer, Southwire Company, has not provided details about its privacy practices and handling of data to Apple. For more information, see the developer’s privacy policy.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


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