# Fan Law Calculator vs EcoMeter Pro

The clearest difference is price: EcoMeter Pro at Free against Fan Law Calculator's $9.99. EcoMeter Pro also leads on update cadence (daily vs every 4 months). Fan Law Calculator's advantage is in-app purchases (none vs 2). On rating, ratings volume, ads and device support there is nothing between them.

EcoMeter Pro is free to download; Fan Law Calculator costs $9.99 up front. EcoMeter Pro sells 2 in-app purchases, starting at $4.99 per month. Fan Law Calculator asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for Fan Law Calculator against 5.0 for EcoMeter Pro. Both are backed by a comparable volume of ratings — 4 and 2 respectively.

Fan Law Calculator ships an update every 4 months, EcoMeter Pro daily. The most recent releases landed on November 2, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | Fan Law Calculator | EcoMeter Pro |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | [5.0 (4 ratings)](https://appshunter.io/ios/app/fan-law-calculator/id1114006510/reviews) | [5.0 (2 ratings)](https://appshunter.io/ios/app/ecometer-pro/id6755688522/reviews) |
| Number of ratings | **4** | 2 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Daily** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 0 MB | 51 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Pheinex, LLC](https://appshunter.io/developer/996932317) | [KYLE T WHITE](https://appshunter.io/developer/1855567390) |

## What reviewers say

### Fan Law Calculator

[App page](https://appshunter.io/ios/app/fan-law-calculator/id1114006510)

Quickly estimate performance changes in HVAC systems based on variations in airflow and RPM. Uses standard fan law equations for calculations. Input current values and see results update instantly.

**Highlights:** Estimate airflow and RPM impact, Uses standard fan law equations, Automatic calculation updates, Graph view for value adjustment, Input current airflow, RPM, pressure, and current/power

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

**In-app purchases:** none


### EcoMeter Pro

[App page](https://appshunter.io/ios/app/ecometer-pro/id6755688522)

This tool streamlines HVAC airflow balancing and reporting for technicians. It guides users through proportional balancing and generates professional PDF reports for residential and light commercial applications, ensuring speed and accuracy in the field.

**Highlights:** Proportional airflow balancing workflow, Standalone single-system balance reports (PDF), Outlet-level balancing summaries, Fast, repeatable field calculations, Customizable reports with company branding

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| EcoMeter Standard – Monthly | $4.99 | per month |
| EcoMeter Standard – Yearly | $39.99 | per year |


## Frequently asked questions

### Is Fan Law Calculator free?

Fan Law Calculator costs $9.99, with no in-app purchases.

### Is EcoMeter Pro free?

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

### Which has better reviews, Fan Law Calculator or EcoMeter Pro?

Fan Law Calculator and EcoMeter Pro are both rated 5.0 out of 5 on the App Store, from 4 and 2 ratings respectively.

### Do Fan Law Calculator or EcoMeter Pro have ads?

Neither Fan Law Calculator nor EcoMeter Pro shows ads.

### Which is updated more often, Fan Law Calculator or EcoMeter Pro?

Fan Law Calculator ships an update every 4 months, and EcoMeter Pro daily. Most recently, Fan Law Calculator was updated on November 2, 2026 and EcoMeter Pro on November 5, 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.*