# Air Flow Conversion Calculator vs ULT

The clearest difference is price: ULT at Free against Air Flow Conversion Calculator's $2.99. ULT also leads on update cadence (every 14 months vs every 47 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

ULT is free to download; Air Flow Conversion Calculator costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Air Flow Conversion Calculator ships an update every 47 months, ULT every 14 months. The most recent releases landed on November 2, 2026 and November 7, 2026 respectively.

## The numbers

| Metric | Air Flow Conversion Calculator | ULT |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | **[3.5 (11 ratings)](https://appshunter.io/ios/app/air-flow-conversion-calculator/id1375810553/reviews)** | — |
| Number of ratings | **11** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 47 months | **Every 14 months** |
| Monetization | Paid | — |
| Size | 8 MB | 11 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Nitrio](https://appshunter.io/developer/321121189) | [Stefan Jakschik](https://appshunter.io/developer/1564456337) |

## What reviewers say

### Air Flow Conversion Calculator

[App page](https://appshunter.io/ios/app/air-flow-conversion-calculator/id1375810553)

Easily calculate air velocity and airflow volume for various duct types. Input dimensions and units, and get instant results for HVAC and ventilation applications.

**Highlights:** Calculate air velocity and airflow volume, Support for circular and rectangular ducts, Multiple unit options for velocity, volume, and dimensions, Instant result display, Useful for HVAC and ventilation

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

**In-app purchases:** none


### ULT

[App page](https://appshunter.io/ios/app/ult-calculator/id1564456335)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Air Flow Conversion Calculator free?

Air Flow Conversion Calculator costs $2.99, with no in-app purchases.

### Is ULT free?

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

### Do Air Flow Conversion Calculator or ULT have ads?

Neither Air Flow Conversion Calculator nor ULT shows ads.

### Which is updated more often, Air Flow Conversion Calculator or ULT?

Air Flow Conversion Calculator ships an update every 47 months, and ULT every 14 months. Most recently, Air Flow Conversion Calculator was updated on November 2, 2026 and ULT on November 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.*