# Duct Size Calculator - HVAC — A tool for HVAC engineers

> HVAC duct sizing calculator for airflow, pressure drop, and velocity. (iPhone/iPad app by Ionut Beleiu.)

- Source: https://appshunter.io/ios/app/duct-size-calculator-hvac/id1253419635 (this page in markdown: same URL + `.md`)
- Developer: [Ionut Beleiu](https://appshunter.io/developer/1253419634)
- Category: Utilities, Productivity
- Price: $5.99
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 4+
- Requires: iOS 10.0 · 7 MB
- Languages: American English
- Released: 2017-06-29
- Data updated: 2026-06-24
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/duct-size-calculator-hvac/id1253419635/reviews.md

## What is Duct Size Calculator?

Duct Size Calculator is a useful application tool designed for HVAC professionals for performing quick sizing analysis. This Duct Sizer app allows you to calculate the flow rate, duct size, pressure drop and velocity for HVAC ductwork (like a classic cardboard ductulator).

NOTE:  Duct Size Calculator is using Imperial Units. 

In the “Size By Airflow” tab you can input the airflow, friction or velocity and the aspect ratio. The app calculate the round (diameter) dimension and the equivalent rectangular diameter based on aspect ratio that you desire. It also calculate the velocity (if you input the friction) and the friction (if you input the velocity)

In the “Size By Dimension” tab you can analyse an existing duct system. You have the option to enter either a round duct diameter or rectangular duct lengths and you also can chose to enter between airflow and velocity. The Duct Size Calculator app calculate the friction and either the velocity either the airflow based on your inputs.

 In "Pressure Drop" tab, you can convert between duct length, pressure drop, and friction find out the pressure drop of a given installation. You can also calculate the maximum duct length that can be used at a desired pressure drop. 

In “Settings” tab you can select the duct material that will automatically adjust the roughness value. Roughness value can be manually input as well. You can also set the temperature and the air pressure values. 
	
 This application uses slider controls that allow you to quickly increment or decrement the input values and immediately observe the calculated results. You can also use the text field to enter the precise value.

You can navigate through the app by pressing the tab bar items or sliders left/right. 

If you have any suggestions to improve this Duct Size Calculator or if you are not fully satisfied with it please email us at ductsizecalculator@gmail.com before posting any negative reviews. Thank you.

Icons on this app are made by Icons8 team.

## Key features

- Calculate airflow, duct size, pressure drop, and velocity
- Size by airflow or duct dimensions
- Convert between duct length, pressure drop, and friction
- Select duct material for roughness adjustment
- Set temperature and air pressure values
- Imperial units support
- Slider and text field input


## Frequently asked questions about Duct Size Calculator

### What is Duct Size Calculator used for?

Duct Size Calculator is a tool for HVAC professionals to perform quick sizing analysis. It helps calculate airflow rate, duct size, pressure drop, and velocity for HVAC ductwork.

### Does Duct Size Calculator support metric units?

No, Duct Size Calculator currently uses Imperial Units only. The app description explicitly states this limitation.

### How does Duct Size Calculator handle duct material?

In the Settings tab, you can select the duct material, which automatically adjusts the roughness value. You also have the option to manually input the roughness value.

### What devices is Duct Size Calculator available on?

Duct Size Calculator is available for iPhone and iPod devices.

### What is the price of Duct Size Calculator?

Duct Size Calculator is a paid application priced at $5.99.

### How often is Duct Size Calculator updated?

The latest version is 1.2, released on August 25, 2017. The app was initially released on June 29, 2017, indicating infrequent updates.

### What is the age rating for Duct Size Calculator?

Duct Size Calculator has an age rating of 4+, making it suitable for a wide range of users.

### How can I provide feedback or suggestions for Duct Size Calculator?

You can email your suggestions to ductsizecalculator@gmail.com before posting any negative reviews. The developers are seeking feedback for improvement.

## Version history (last 2 releases)

### 1.2 — 2017-08-25

This app has been updated by Apple to display the Apple Watch app icon.

- user interface design completely changed 
- fix a bug on Pressure drop / Duct length conversion tab

### 1.0 — 2017-06-29

No release notes.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-24.*