# Southwire® Voltage Drop Calc — Southwire Calculator

> Electrical circuit wire sizing calculator for voltage drop and ampacity. (iPhone/iPad app by Southwire Company.)

- Source: https://appshunter.io/ios/app/southwire-voltage-drop-calc/id440338420 (this page in markdown: same URL + `.md`)
- Developer: [Southwire Company](https://appshunter.io/developer/440338423)
- Category: Utilities, Productivity
- Price: Free
- Rating: 4.58/5 from 1,462 App Store ratings · 52 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.0 · 10 MB
- Languages: English
- Released: 2011-06-02
- Data updated: 2026-08-27
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/southwire-voltage-drop-calc/id440338420/reviews.md

## What is Southwire® Voltage Drop Calc?

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.

## Key features

- Determine wire size for voltage drop
- Calculate voltage drop for conductor runs
- Limit wire size by voltage drop
- Limit wire size by NEC ampacity
- Supports AWG and KCMIL sizes

## What do users think of Southwire® Voltage Drop Calc?

Overall sentiment: neutral

**Pros**

- 🚀 Quick and useful
- 🚀 Great Quick Reference
- 👍 A must have app for electricians
- 👍 Love These
- 👍 Electrical Engineer
- 👍 Awesome app
- 👍 Safer
- 👍 Useful
- 👍 Handy
- 👍 Great App
- 👍 Dependable app
- 👍 Electrician tech
- 👍 Solid and simple to use app
- 👍 Great app

**Cons**

- 🐛 Motor starting Voltage drop
- 🐛 Useless!
- 🐛 Won't work
- 🐛 How to use
- 🐛 Confused
- 🐛 Bad app
- 🐛 Bad
- 🐛 Not applicable for Residential
- 🐛 Electrician
- 🐛 Terrible
- 🐛 Not working
- 🐛 What??
- 🐛 Terrible
- 🐛 Don't work
- 🐛 Terrible
- 🐛 Choice Between AWG and Metric wire Gauge
- 🐛 Updated app not so simple
- 🐛 The last version was better
- 🐛 App
- 🐛 Terrible
- 🐛 Voltage drop calculator
- 🐛 IOS 8
- 🐛 One flaw
- 🐛 Worst app ever
- 🐛 Average

**Commonly reported bugs**

- Useless!
- Won't work
- How to use
- Confused
- Bad app
- Bad
- Not applicable for Residential
- Electrician
- Terrible
- Not working
- What??
- Terrible
- Don't work
- Terrible
- Choice Between AWG and Metric wire Gauge
- Updated app not so simple
- The last version was better
- App
- Terrible
- Voltage drop calculator
- IOS 8
- One flaw
- Worst app ever
- Average

**Most requested features**

- Motor starting Voltage drop calculation
- Metric wire size options

## Recent user reviews (10 of 52)

All indexed reviews: https://appshunter.io/ios/app/southwire-voltage-drop-calc/id440338420/reviews.md

### 5/5 — Quick and useful

*2025-07-09, version 3.2.2*

I’ve used this app for many projects over the years. Love that it has AC and DC options. Used it for regular line voltage, but also solar 400v dc, battery storage 48v dc and automotive 12v dc.

### 5/5 — Great Quick Reference

*2025-02-18, version 3.2.2*

I use this app so often. It is a great reference tool.

### 3/5 — Motor starting Voltage drop

*2025-01-17, version 3.2.2*

Motors have minimum starting voltage drop to 90% of the motors nameplate voltage.  The program does not allow inputting a starting current to calculate the starting Voltage drop.

### 3/5 — Quick and Easy!

*2023-05-12, version 3.1.3*

This is a great field use tool to figure out wire size on the fly!

### 5/5 — A must have app for electricians

*2022-02-11, version 3.1.3*

I use this app for my job as an industrial electrician.  It works great!  It is a time saver.

### 5/5 — Love These

*2022-01-11, version 3.1.3*

It’s good. Thanks to Southwire for allowing me such generous computing capabilities on my iPhone. Five stars earned.

### 5/5 — Electrical Engineer

*2021-12-28, version 3.1.3*

I use every day in the field.

### 5/5 — Awesome app

*2021-12-06, version 3.1.3*

Awesome app

### 5/5 — Safer

*2021-10-02, version 3.1.3*

Nice to have this
Much safer then trying to remember or look up to fine the correct information and it’s right on my phone 
Thank you for offering this
By the way your wire is all that I will use

### 5/5 — Useful

*2021-09-21, version 3.1.3*

Nice to be able to sit on the site and run the various options to figure out what size cable to run

## Frequently asked questions about Southwire® Voltage Drop Calc

### What does the Southwire Voltage Drop Calc app do?

This app helps you determine the correct wire size for electrical circuits. It calculates the appropriate wire size based on specified voltage drop limits and the current carrying capacity (ampacity) of the circuit, ensuring compliance with National Electrical Code (NEC) standards.

### What are the key features of this voltage drop calculator?

The app allows you to determine the wire size needed to meet specific voltage drop limits. It can also calculate the voltage drop for a given conductor run. Calculations are limited by both voltage drop and NEC ampacity, and it supports AWG and KCMIL wire sizes.

### Is this app free to use?

Yes, the Southwire Voltage Drop Calc app is available for free. There are no in-app purchases or advertisements mentioned, indicating it is a completely free utility.

### What types of wire sizes does this app support?

The calculator is designed specifically for applications using American Wire Gauge (AWG) and Kilocircle Mil (KCMIL) sizes. It does not support other wire sizing standards.

### Who would benefit from using this app?

This app is beneficial for electricians, electrical engineers, and anyone involved in designing or installing electrical circuits. It helps ensure circuits are correctly sized for safety and efficiency according to industry standards.

## Version history (last 5 releases)

### 3.2.4 — 2026-07-01

Behind the scenes updates.

### 3.2.3 — 2025-07-24

New graphics.

### 3.2.2 — 2024-12-11

New banner.

### 3.2.1 — 2024-10-23

Behind the scenes update

### 3.2 — 2024-10-09

Behind the scenes changes.

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## More apps by Southwire Company

- [Partial Reel Calculator](https://appshunter.io/ios/app/partial-reel-calculator/id489177969)
- [Southwire® Conduit Fill Calc](https://appshunter.io/ios/app/southwire-conduit-fill-calc/id509204523)
- [Southwire® MCAP® Savings Calc](https://appshunter.io/ios/app/southwire-mcap-savings-calc/id509207536)
- [Proof Positive© Copper](https://appshunter.io/ios/app/proof-positive-copper/id518391353)
- [Southwire® Conversion Calc](https://appshunter.io/ios/app/southwire-conversion-calc/id545756420)

All apps by Southwire Company: https://appshunter.io/developer/440338423

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-27.*