# HVAC ToolKit vs Duct Calculator

The clearest difference is price: Duct Calculator at Free against HVAC ToolKit's $9.99. Duct Calculator also leads on rating (4.7 vs 1.0) and ratings volume (3 vs 1). HVAC ToolKit's advantage is in-app purchases (none vs 1) and update cadence (every 3 months vs every 10 months). On ads and device support there is nothing between them.

Duct Calculator is free to download; HVAC ToolKit costs $9.99 up front. Duct Calculator sells 1 one-off in-app purchase. HVAC ToolKit asks for nothing beyond the download.

Duct Calculator holds the better App Store score, 4.7 against 1.0. Both are backed by a comparable volume of ratings — 1 and 3 respectively.

HVAC ToolKit ships an update every 3 months, Duct Calculator every 10 months. The most recent releases landed on October 14, 2026 and October 26, 2026 respectively.

## The numbers

| Metric | HVAC ToolKit | Duct Calculator |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | [1.0 (1 ratings)](https://appshunter.io/ios/app/hvac-toolkit/id1623246775/reviews) | **[4.7 (3 ratings)](https://appshunter.io/ios/app/duct-calculator-hvac-sizing/id6756908372/reviews)** |
| Number of ratings | 1 | **3** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 10 months |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 60 MB | 44 MB |
| Requires iOS | **12.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Mohamad Jaber](https://appshunter.io/developer/1623246777) | [Sachinbhai Surani](https://appshunter.io/developer/1838685550) |

## What reviewers say

### HVAC ToolKit

[App page](https://appshunter.io/ios/app/hvac-toolkit/id1623246775)

This application provides HVAC engineers with tools for design checks and quick calculations. It offers various calculators for ducting friction, pipe sizing, ventilation, and heat load estimations, with clear instructions and formulas. Users can switch between metric and imperial units, and English or Arabic languages.

**Highlights:** Friction loss calculations, Pipe sizing tools, Ventilation and pressurization calculators, Heat load and pump head estimations, Metric/Imperial unit support, English/Arabic language options

**Features:** macOS Compatibility

**In-app purchases:** none


### Duct Calculator

[App page](https://appshunter.io/ios/app/duct-calculator-hvac-sizing/id6756908372)

This professional HVAC utility assists engineers and technicians with precise duct sizing and airflow calculations for ventilation systems. It simplifies essential calculations for both design and installation work, improving on-site efficiency.

**Highlights:** Calculate duct sizes using airflow (CFM) and velocity (FPM), Supports rectangular and round duct sizing in inches, Determine air flow rate in CFM, Calculate air velocity in FPM, Simple interface for fast on-site calculations

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime premium | $9.99 | one-time |


## Frequently asked questions

### Is HVAC ToolKit free?

HVAC ToolKit costs $9.99, with no in-app purchases.

### Is Duct Calculator free?

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

### Which has better reviews, HVAC ToolKit or Duct Calculator?

Duct Calculator is rated higher. HVAC ToolKit averages 1.0 out of 5 from 1 ratings, while Duct Calculator averages 4.7 from 3 ratings.

### Do HVAC ToolKit or Duct Calculator have ads?

Neither HVAC ToolKit nor Duct Calculator shows ads.

### Which is updated more often, HVAC ToolKit or Duct Calculator?

HVAC ToolKit ships an update every 3 months, and Duct Calculator every 10 months. Most recently, HVAC ToolKit was updated on October 14, 2026 and Duct Calculator on October 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.*