# Oxygen Cylinder Autonomy Calc vs Nitrox Virtual Analyzer

The clearest difference is update cadence: Oxygen Cylinder Autonomy Calc at every 2 months against Nitrox Virtual Analyzer's every 24 months. Oxygen Cylinder Autonomy Calc also leads on iOS requirement (9.2 vs 13.0). On price, ads, in-app purchases and device support there is nothing between them.

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

Oxygen Cylinder Autonomy Calc ships an update every 2 months, Nitrox Virtual Analyzer every 24 months. The most recent releases landed on September 13, 2026 and May 19, 2026 respectively.

## The numbers

| Metric | Oxygen Cylinder Autonomy Calc | Nitrox Virtual Analyzer |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 24 months |
| Size | 16 MB | 6 MB |
| Requires iOS | **9.2** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [DIGITAL IDEATORS INNOVATIONS SRL](https://appshunter.io/developer/1417180570) | [James Costello](https://appshunter.io/developer/1504868572) |

## What reviewers say

### Oxygen Cylinder Autonomy Calc

[App page](https://appshunter.io/ios/app/oxygen-cylinder-autonomy-calc/id1257704597)

**Features:** macOS Compatibility

**In-app purchases:** none


### Nitrox Virtual Analyzer

[App page](https://appshunter.io/ios/app/nitrox-virtual-analyzer/id1505174941)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Oxygen Cylinder Autonomy Calc free?

Oxygen Cylinder Autonomy Calc is free to download, with no in-app purchases.

### Is Nitrox Virtual Analyzer free?

Nitrox Virtual Analyzer is free to download, with no in-app purchases.

### Do Oxygen Cylinder Autonomy Calc or Nitrox Virtual Analyzer have ads?

Neither Oxygen Cylinder Autonomy Calc nor Nitrox Virtual Analyzer shows ads.

### Which is updated more often, Oxygen Cylinder Autonomy Calc or Nitrox Virtual Analyzer?

Oxygen Cylinder Autonomy Calc ships an update every 2 months, and Nitrox Virtual Analyzer every 24 months. Most recently, Oxygen Cylinder Autonomy Calc was updated on September 13, 2026 and Nitrox Virtual Analyzer on May 19, 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.*