# Instrument Toolbox vs GasUnits

The clearest difference is price: GasUnits at Free against Instrument Toolbox's $1.99. Instrument Toolbox's advantage is iOS requirement (13.0 vs 15.1). On update cadence, ads, in-app purchases and device support there is nothing between them.

GasUnits is free to download; Instrument Toolbox costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Instrument Toolbox ships an update weekly, GasUnits every 10 days. The most recent releases landed on October 9, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Instrument Toolbox | GasUnits |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/gasunits/id6762513689/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Weekly** | Every 10 days |
| Monetization | Paid | **Free** |
| Size | 8 MB | 30 MB |
| Requires iOS | **13.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [立娜 王](https://appshunter.io/developer/1761096632) | [Vivek Chandra](https://appshunter.io/developer/461237208) |

## 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


### GasUnits

[App page](https://appshunter.io/ios/app/gasunits/id6762513689)

This app simplifies complex natural gas and LNG unit conversions for industry professionals. It accurately converts over 90 volume, rate, and price units, offering precise results and composition-based estimates. Easily copy formatted results for reports and models.

**Highlights:** Converts 90+ gas volume, rate, and price units, Supports three standard gas heating values, Calculates barrels of oil equivalent, Provides composition-based estimates, Fast, intuitive, and error-proof design, Copy results for reports and models

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

**In-app purchases:** none


## Frequently asked questions

### Is Instrument Toolbox free?

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

### Is GasUnits free?

GasUnits is free to download, with no in-app purchases.

### Do Instrument Toolbox or GasUnits have ads?

Neither Instrument Toolbox nor GasUnits shows ads.

### Which is updated more often, Instrument Toolbox or GasUnits?

Instrument Toolbox ships an update weekly, and GasUnits every 10 days. Most recently, Instrument Toolbox was updated on October 9, 2026 and GasUnits on October 7, 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.*