# Instrument Toolbox vs My LoopCal

The clearest difference is price: My LoopCal at Free against Instrument Toolbox's $1.99. Instrument Toolbox's advantage is in-app purchases (none vs 3) and iOS requirement (13.0 vs 17.0). On update cadence, ads and device support there is nothing between them.

My LoopCal is free to download; Instrument Toolbox costs $1.99 up front. My LoopCal sells 3 in-app purchases, starting at $2.99 per month. Instrument Toolbox asks for nothing beyond the download.

Instrument Toolbox ships an update weekly, My LoopCal every 10 days. The most recent releases landed on November 8, 2026 and November 10, 2026 respectively.

## The numbers

| Metric | Instrument Toolbox | My LoopCal |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/my-loopcal-4-20ma-calibration/id6792422682/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Weekly** | Every 10 days |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 8 MB | 3 MB |
| Requires iOS | **13.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [立娜 王](https://appshunter.io/developer/1761096632) | [Neobile LLC](https://appshunter.io/developer/1080490647) |

## What reviewers say

### Instrument Toolbox

[App page](https://appshunter.io/ios/app/instrument-toolbox/id6698856248)

A professional calculator designed for industrial control, automation, and instrumentation engineers. It offers quick conversions and calculations for gas concentration, units, steam properties, flange levels, and pipeline flow. Ideal for both field debugging and engineering design.

**Highlights:** PPM to mg/m³ conversion with compensation, Industrial unit conversion (pressure, volume, temp, etc.), Saturated steam pressure and density calculator, Flange level migration calculations, Pipeline flow and velocity calculator, Real-time calculation results

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### My LoopCal

[App page](https://appshunter.io/ios/app/my-loopcal-4-20ma-calibration/id6792422682)

Streamline 4-20mA loop checks with guided calibration worksheets and instant signal conversion. Generate PDF reports, manage instrument history, and perform loop power calculations offline. Designed for field technicians.

**Highlights:** Guided calibration worksheets (3-21 points), As-found/as-left runs with error reporting, Signal conversion (4-20mA, 0-10V, etc.), PDF and CSV report generation, Instrument history and calibration reminders, Loop power calculations, Offline functionality

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $2.99 | per month |
| Annual | $9.99 | per year |
| Lifetime | $19.99 | one-time |


## Frequently asked questions

### Is Instrument Toolbox free?

Instrument Toolbox costs $1.99, with no in-app purchases.

### Is My LoopCal free?

My LoopCal is free to download, with in-app purchases available.

### Do Instrument Toolbox or My LoopCal have ads?

Neither Instrument Toolbox nor My LoopCal shows ads.

### Which is updated more often, Instrument Toolbox or My LoopCal?

Instrument Toolbox ships an update weekly, and My LoopCal every 10 days. Most recently, Instrument Toolbox was updated on November 8, 2026 and My LoopCal on November 10, 2026.

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