# Duct Calculator vs Quietflex Ductulator

The clearest difference is price: Quietflex Ductulator at Free against Duct Calculator's $19.99. Quietflex Ductulator also leads on rating (5.0 vs 4.5) and update cadence (every 3 days vs every 2 months). Duct Calculator's advantage is ratings volume (189 vs 1). On ads, in-app purchases, monetization model and device support there is nothing between them.

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

Quietflex Ductulator holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Duct Calculator has 189 ratings behind it against 1, so its average is the more settled of the two.

Duct Calculator ships an update every 2 months, Quietflex Ductulator every 3 days. The most recent releases landed on October 22, 2026 and September 26, 2026 respectively.

## The numbers

| Metric | Duct Calculator | Quietflex Ductulator |
| --- | --- | --- |
| Price | $19.99 | **Free** |
| Rating | [4.5 (189 ratings)](https://appshunter.io/ios/app/duct-calculator/id1078238132/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/quietflex-ductulator/id1490925984/reviews)** |
| Number of ratings | **189** | 1 |
| Positive reviews | 57.1% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 days** |
| Monetization | Free | Free |
| Size | 2 MB | 30 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) | [Goodman Manufacturing L.P.](https://appshunter.io/developer/1485904991) |

## 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


### Quietflex Ductulator

[App page](https://appshunter.io/ios/app/quietflex-ductulator/id1490925984)

This utility app helps HVAC professionals and enthusiasts quickly calculate essential airflow metrics for various duct sizes. It provides CFM, FPM, and FL values, simplifying HVAC system design and analysis.

**Highlights:** Calculate CFM, Calculate FPM, Calculate FL, Supports different duct diameters, HVAC system analysis

**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 Quietflex Ductulator free?

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

### Which has better reviews, Duct Calculator or Quietflex Ductulator?

Quietflex Ductulator is rated higher. Duct Calculator averages 4.5 out of 5 from 189 ratings, while Quietflex Ductulator averages 5.0 from 1 ratings.

### Do Duct Calculator or Quietflex Ductulator have ads?

Neither Duct Calculator nor Quietflex Ductulator shows ads.

### Which is updated more often, Duct Calculator or Quietflex Ductulator?

Duct Calculator ships an update every 2 months, and Quietflex Ductulator every 3 days. Most recently, Duct Calculator was updated on October 22, 2026 and Quietflex Ductulator on September 26, 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.*