# Southwire® Voltage Drop Calc vs Pump Tech Toolbox

The clearest difference is device support: Southwire® Voltage Drop Calc at 3 against Pump Tech Toolbox's 1. Southwire® Voltage Drop Calc also leads on iOS requirement (15.0 vs 26.0). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Southwire® Voltage Drop Calc ships an update every 2 months, Pump Tech Toolbox monthly. The most recent releases landed on October 30, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | Southwire® Voltage Drop Calc | Pump Tech Toolbox |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (1.5K ratings)](https://appshunter.io/ios/app/southwire-voltage-drop-calc/id440338420/reviews)** | — |
| Number of ratings | **1.5K** | — |
| Positive reviews | 49.1% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Monthly** |
| Monetization | Free | — |
| Size | 10 MB | 23 MB |
| Requires iOS | **15.0** | 26.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Southwire Company](https://appshunter.io/developer/440338423) | [Torridon Systems LLC](https://appshunter.io/developer/6802657357) |

## What reviewers say

### Southwire® Voltage Drop Calc

[App page](https://appshunter.io/ios/app/southwire-voltage-drop-calc/id440338420)

Calculate the appropriate wire size for electrical circuits. This tool helps determine wire size based on voltage drop and current carrying capacity, ensuring compliance with NEC ampacity limits.

**Highlights:** 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

**Features:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

- 🚀 Quick and useful
- 🚀 Great Quick Reference
- 👍 A must have app for electricians
- 👍 Love These
- 👍 Electrical Engineer

**What reviewers complain about**

- 🐛 Motor starting Voltage drop
- 🐛 Useless!
- 🐛 Won't work
- 🐛 How to use
- 🐛 Confused

**Reported bugs**

- Useless!
- Won't work
- How to use
- Confused
- Bad app

**Requested features**

- Motor starting Voltage drop calculation
- Metric wire size options


### Pump Tech Toolbox

[App page](https://appshunter.io/ios/app/pump-tech-toolbox/id6805018515)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Southwire® Voltage Drop Calc free?

Southwire® Voltage Drop Calc is free to download, with no in-app purchases.

### Is Pump Tech Toolbox free?

Pump Tech Toolbox is free to download, with no in-app purchases.

### Do Southwire® Voltage Drop Calc or Pump Tech Toolbox have ads?

Neither Southwire® Voltage Drop Calc nor Pump Tech Toolbox shows ads.

### Which is updated more often, Southwire® Voltage Drop Calc or Pump Tech Toolbox?

Southwire® Voltage Drop Calc ships an update every 2 months, and Pump Tech Toolbox monthly. Most recently, Southwire® Voltage Drop Calc was updated on October 30, 2026 and Pump Tech Toolbox on October 29, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*