# CO2 Filter Calc vs IGC H₂

CO2 Filter Calc and IGC H₂ are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

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

CO2 Filter Calc ships an update weekly, IGC H₂ every 5 days. The most recent releases landed on October 18, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | CO2 Filter Calc | IGC H₂ |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Weekly | **Every 5 days** |
| Size | 1 MB | 17 MB |
| Requires iOS | 14.0 | **13.4** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [TOMCO2 Systems Company](https://appshunter.io/developer/1683554220) | [Industrial Gas Consultants LLC](https://appshunter.io/developer/1725282233) |

## What reviewers say

### CO2 Filter Calc

[App page](https://appshunter.io/ios/app/co2-filter-calc/id6448122642)

**Features:** macOS Compatibility

**In-app purchases:** none


### IGC H₂

[App page](https://appshunter.io/ios/app/igc-h-co-unit-conversion-app/id6475814418)

**In-app purchases:** none


## Frequently asked questions

### Is CO2 Filter Calc free?

CO2 Filter Calc is free to download, with no in-app purchases.

### Is IGC H₂ free?

IGC H₂ is free to download, with no in-app purchases.

### Do CO2 Filter Calc or IGC H₂ have ads?

Neither CO2 Filter Calc nor IGC H₂ shows ads.

### Which is updated more often, CO2 Filter Calc or IGC H₂?

CO2 Filter Calc ships an update weekly, and IGC H₂ every 5 days. Most recently, CO2 Filter Calc was updated on October 18, 2026 and IGC H₂ on October 15, 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.*