# Duct Calculator vs RiDATA

The clearest difference is price: RiDATA at Free against Duct Calculator's $19.99. RiDATA also leads on iOS requirement (8.0 vs 15.0). Duct Calculator's advantage is rating (4.5 vs 3.3) and review sentiment (57% vs 17%). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

RiDATA is free to download; Duct Calculator costs $19.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Duct Calculator holds the better App Store score, 4.5 against 3.3. That said, the two scores are not equally well evidenced: Duct Calculator has 189 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 57% of Duct Calculator's written reviews are positive against 17% of RiDATA's.

Both ship on a similar rhythm, roughly every 2 months. Both last shipped on November 2, 2026.

## The numbers

| Metric | Duct Calculator | RiDATA |
| --- | --- | --- |
| Price | $19.99 | **Free** |
| Rating | **[4.5 (189 ratings)](https://appshunter.io/ios/app/duct-calculator/id1078238132/reviews)** | [3.3 (3 ratings)](https://appshunter.io/ios/app/ridata/id1136069132/reviews) |
| Number of ratings | **189** | 3 |
| Positive reviews | **57.1% of reviews** | 16.7% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | Free | Free |
| Size | 2 MB | 45 MB |
| Requires iOS | 15.0 | **8.0** |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Pheinex, LLC](https://appshunter.io/developer/996932317) | [Siliconmotion](https://appshunter.io/developer/1050091822) |

## What reviewers say

### Duct Calculator

[App page](https://appshunter.io/ios/app/duct-calculator/id1078238132)

This app allows HVAC professionals to quickly and accurately size new ducts or calculate the performance of existing ones. It supports both round and rectangular ductwork, offering precise calculations through direct entry or intuitive sliders. The tool provides live updates and outputs key performance metrics.

**Highlights:** Size round and rectangular ductwork, Adjust airflow, diameter, width, and height, Direct number entry for precision, Lockable dimensions for 'what-if' scenarios, Live update of calculated values, Outputs velocity and pressure drop, Supports IP and SI units

**Features:** Vision Pro support

**In-app purchases:** none


### RiDATA

[App page](https://appshunter.io/ios/app/ridata/id1136069132)

Expand your iOS device's storage with an external RiDATA device. Easily transfer and manage photos, videos, audio, and documents across different platforms and devices.

**Highlights:** External storage device compatibility, File exchange across devices/platforms, Picture browser, Video player, Audio player, Document browser, Camera function

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Duct Calculator free?

Duct Calculator costs $19.99, with no in-app purchases.

### Is RiDATA free?

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

### Which has better reviews, Duct Calculator or RiDATA?

Duct Calculator is rated higher. Duct Calculator averages 4.5 out of 5 from 189 ratings, while RiDATA averages 3.3 from 3 ratings.

### Do Duct Calculator or RiDATA have ads?

Neither Duct Calculator nor RiDATA shows ads.

### Which is updated more often, Duct Calculator or RiDATA?

Duct Calculator ships an update every 2 months, and RiDATA every 2 months. Most recently, Duct Calculator was updated on November 2, 2026 and RiDATA on November 2, 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.*