# DuctSizer vs AppAirTools

The clearest difference is price: AppAirTools at Free against DuctSizer's $4.99. DuctSizer's advantage is in-app purchases (none vs 1) and iOS requirement (12.0 vs 15.0). On update cadence, ads and device support there is nothing between them.

AppAirTools is free to download; DuctSizer costs $4.99 up front. AppAirTools sells 1 in-app purchase, starting at $0.99 per month. DuctSizer asks for nothing beyond the download.

DuctSizer ships an update every 4 days, AppAirTools every 3 days. The most recent releases landed on October 14, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | DuctSizer | AppAirTools |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 days | **Every 3 days** |
| Monetization | Paid | — |
| Size | 57 MB | 52 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Mulberrysoft](https://appshunter.io/developer/1612779919) | [wanchai khwunkhum](https://appshunter.io/developer/6807079696) |

## What reviewers say

### DuctSizer

[App page](https://appshunter.io/ios/app/ductsizer/id6467117263)

This utility app provides a quick and accurate ductulator for calculating equivalent round and rectangular duct sizes. It supports both Imperial and SI units, offering a simple finger-slide interface for fast computations.

**Highlights:** Quick duct size calculations, Accurate results, Equivalent round and rectangular sizes, IP and SI unit support, Finger slide interface

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

**In-app purchases:** none


### AppAirTools

[App page](https://appshunter.io/ios/app/appairtools/id6807079694)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| สมาชิกรายเดือน | $0.99 | per month |


## Frequently asked questions

### Is DuctSizer free?

DuctSizer costs $4.99, with no in-app purchases.

### Is AppAirTools free?

AppAirTools is free to download, with in-app purchases available.

### Do DuctSizer or AppAirTools have ads?

Neither DuctSizer nor AppAirTools shows ads.

### Which is updated more often, DuctSizer or AppAirTools?

DuctSizer ships an update every 4 days, and AppAirTools every 3 days. Most recently, DuctSizer was updated on October 14, 2026 and AppAirTools on October 17, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*