# Trigonometry Help vs Southwire® Voltage Drop Calc

The clearest difference is price: Southwire® Voltage Drop Calc at Free against Trigonometry Help's $1.99. Southwire® Voltage Drop Calc also leads on in-app purchases (none vs 3) and update cadence (every 2 months vs every 13 months). Trigonometry Help's advantage is review sentiment (91% vs 48%) and iOS requirement (10.0 vs 15.0). On rating, ads and device support there is nothing between them.

Southwire® Voltage Drop Calc is free to download; Trigonometry Help costs $1.99 up front. Trigonometry Help sells 3 one-off in-app purchases. Southwire® Voltage Drop Calc asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.7 for Trigonometry Help against 4.6 for Southwire® Voltage Drop Calc. Both are backed by a comparable volume of ratings — 480 and 1.5K respectively. Written reviews are what separate them: 91% of Trigonometry Help's written reviews are positive against 48% of Southwire® Voltage Drop Calc's.

Trigonometry Help ships an update every 13 months, Southwire® Voltage Drop Calc every 2 months. Both last shipped on October 20, 2026.

## The numbers

| Metric | Trigonometry Help | Southwire® Voltage Drop Calc |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | **[4.7 (480 ratings)](https://appshunter.io/ios/app/trigonometry-help/id411415648/reviews)** | [4.6 (1.5K ratings)](https://appshunter.io/ios/app/southwire-voltage-drop-calc/id440338420/reviews) |
| Number of ratings | 480 | **1.5K** |
| Positive reviews | **91.0% of reviews** | 48.1% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 13 months | **Every 2 months** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 21 MB | 10 MB |
| Requires iOS | **10.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | +4 | 4+ |
| Developer | [Armchair Engineering](https://appshunter.io/developer/398901339) | [Southwire Company](https://appshunter.io/developer/440338423) |

## What reviewers say

### Trigonometry Help

[App page](https://appshunter.io/ios/app/trigonometry-help/id411415648)

This app helps you quickly solve for unknown angles and sides of right-angled triangles. It provides a workings view for understanding the math, a scale drawing of the triangle, and a reference for basic trigonometric formulas. You can input angles in various formats and choose your desired decimal precision.

**Highlights:** Solve right-angled triangles, Workings view for solutions, Scale drawing of solved triangle, Basic trig formulae reference, Multiple angle input formats, Customizable decimal places

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Trig Help Premium | $0.99 | one-time |
| Trig Help Premium | $1.99 | one-time |
| Trig Help Premium | $3.99 | one-time |

**What reviewers like**

- 🚀 Quick and easy to use
- 👍 User-friendly interface
- 🔧 Helpful for tradesmen and professionals
- ⚙️ Accurate calculations
- 🔍 Convenient for on-site use

**What reviewers complain about**

- 🔢 Limited to right-angled triangles only
- 🔍 Lacks advanced trig functions
- 🔀 No option to rotate/flip the triangle view

**Reported bugs**

- Inconsistent performance on older devices
- Occasional crashes or freezes

**Requested features**

- Support for irregular triangles
- Ability to show step-by-step workings
- Option to switch between degrees/minutes/seconds and decimal values


### 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


## Frequently asked questions

### Is Trigonometry Help free?

Trigonometry Help costs $1.99, and also offers in-app purchases.

### Is Southwire® Voltage Drop Calc free?

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

### Which has better reviews, Trigonometry Help or Southwire® Voltage Drop Calc?

Trigonometry Help is rated higher. Trigonometry Help averages 4.7 out of 5 from 480 ratings, while Southwire® Voltage Drop Calc averages 4.6 from 1.5K ratings.

### Do Trigonometry Help or Southwire® Voltage Drop Calc have ads?

Neither Trigonometry Help nor Southwire® Voltage Drop Calc shows ads.

### Which is updated more often, Trigonometry Help or Southwire® Voltage Drop Calc?

Trigonometry Help ships an update every 13 months, and Southwire® Voltage Drop Calc every 2 months. Most recently, Trigonometry Help was updated on October 20, 2026 and Southwire® Voltage Drop Calc on October 20, 2026.

---

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