# DuctChecker vs Easy Reference Measure

The clearest difference is price: Easy Reference Measure at Free against DuctChecker's $6.99. Easy Reference Measure also leads on update cadence (every 9 days vs every 4 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Easy Reference Measure is free to download; DuctChecker costs $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.

DuctChecker ships an update every 4 months, Easy Reference Measure every 9 days. The most recent releases landed on September 7, 2026 and July 18, 2026 respectively.

## The numbers

| Metric | DuctChecker | Easy Reference Measure |
| --- | --- | --- |
| Price | $6.99 | **Free** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 9 days** |
| Monetization | Paid | — |
| Size | 23 MB | 4 MB |
| Requires iOS | **15.0** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [AIR DESIGN, INC.](https://appshunter.io/developer/923430781) | [Hideo Nose](https://appshunter.io/developer/1616288004) |

## What reviewers say

### DuctChecker

[App page](https://appshunter.io/ios/app/ductchecker/id933593987)

Easily calculate duct dimensions using various engineering methods like constant pressure, static pressure regain, total pressure, and velocity. This tool simplifies complex duct design calculations, typically found in flow diagrams or slide rules.

**Highlights:** Constant pressure method calculation, Static pressure regain method, Total pressure method, Velocity method, Duct dimension determination, Simplified duct design

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

**In-app purchases:** none


### Easy Reference Measure

[App page](https://appshunter.io/ios/app/easy-reference-measure/id6752796869)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is DuctChecker free?

DuctChecker costs $6.99, with no in-app purchases.

### Is Easy Reference Measure free?

Easy Reference Measure is free to download, with no in-app purchases.

### Do DuctChecker or Easy Reference Measure have ads?

Neither DuctChecker nor Easy Reference Measure shows ads.

### Which is updated more often, DuctChecker or Easy Reference Measure?

DuctChecker ships an update every 4 months, and Easy Reference Measure every 9 days. Most recently, DuctChecker was updated on September 7, 2026 and Easy Reference Measure on July 18, 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.*