# Duct Calculator - HVAC Sizing — HVAC duct sizing

> HVAC utility for calculating duct sizes and airflow values. (iPhone/iPad app by Sachinbhai Surani.)

- Source: https://appshunter.io/ios/app/duct-calculator-hvac-sizing/id6756908372 (this page in markdown: same URL + `.md`)
- Developer: [Sachinbhai Surani](https://appshunter.io/developer/1838685550)
- Category: Productivity
- Price: Free with in-app purchases
- Rating: 4.70/5 from 3 App Store ratings
- Age rating: 4+
- Requires: iOS 15.6 · 44 MB
- Languages: American English
- Released: 2025-12-24
- Data updated: 2026-10-12
- Monetization: free with in-app purchases

## What is Duct Calculator?

Duct Calculator is a focused duct sizing tool for HVAC engineers, designers and installation technicians. Enter what you know and get the duct dimensions, airflow or air velocity you need, without a chart or a slide rule.

CALCULATIONS
- Duct size: find the required duct dimensions from airflow (CFM) and air velocity (FPM).
- Airflow: determine the airflow rate in CFM.
- Air velocity: determine velocity in FPM to help verify system performance.

DUCT SHAPES
- Round ducts
- Rectangular ducts
- Results shown in inches

WHO IT IS FOR
- HVAC engineers and designers checking a duct size during design work.
- Installation technicians and contractors who need a quick answer on site.
- Students learning how airflow, velocity and duct size relate.

WHERE IT HELPS
- Sizing a new supply or return run from a known CFM.
- Checking whether an existing duct keeps velocity within your target.
- Comparing a round duct with a rectangular one when space is tight.

SIMPLE BY DESIGN
A clean interface with only the inputs you need, so you get an answer quickly on the job.

Duct Calculator is free to use. An optional one-time upgrade removes ads.

Results are intended as a calculation aid. Always confirm designs against applicable codes and project requirements.

Download Duct Calculator and size your next duct run.

Privacy Policy : https://semiconhub.in/manager/privacy.html
Terms and Condition : https://semiconhub.in/manager/tcondition.html

## Key features

- 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

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

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


## Is Duct Calculator safe?

Not enough ratings yet to assess Duct Calculator.

## Is Duct Calculator legit?

Duct Calculator - HVAC Sizing appears legitimate, with a few gaps. The AppsHunter Legitimacy Score for Duct Calculator is 65 out of 100 points across 7 verification signals from App Store and developer data.


## Frequently asked questions about Duct Calculator

### What is the Duct Calculator app?

Duct Calculator is a professional HVAC utility designed to help engineers and technicians accurately calculate duct sizes and airflow values for ventilation systems. It simplifies essential HVAC calculations for design and installation work.

### What types of ducts can Duct Calculator size?

Duct Calculator supports sizing for both rectangular and circular ducts. The calculations are provided in inches, making it suitable for a wide range of HVAC projects.

### Can Duct Calculator determine airflow rates?

Yes, Duct Calculator can determine air flow rate accurately in CFM (Cubic Feet per Minute) and air velocity in FPM (Feet per Minute). This helps professionals verify system performance and ensure proper ventilation.

### Is Duct Calculator suitable for on-site use?

Yes, the app features a simple interface designed for fast calculations on-site or during design work. It's a reliable and practical tool for heating, ventilation, and air conditioning professionals.

### What devices does Duct Calculator support?

Duct Calculator is available for iPhone, iPad, and iPod. It is designed for Apple devices.

### How often is Duct Calculator updated?

The latest version of Duct Calculator is 1.0, and it was last updated on December 24, 2025. Future updates will likely focus on improvements and new features.

### Does Duct Calculator have ads?

Duct Calculator is free to download and use. An in-app purchase is available to remove advertisements, offering a lifetime ad-free experience.

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

Duct Calculator has an age rating of 4+. This indicates it is suitable for users of all ages, with no mature content.

## Version history (last 2 releases)

### 1.1 — 2026-10-09

• Improved overall performance and stability
• Fixed minor bugs and enhanced user experience

### 1.0 — 2025-12-24

No release notes.

## Apps similar to Duct Calculator

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Ductalator](https://appshunter.io/ios/app/ductalator/id6747029541) | — | Free | Productivity |
| [PT Ductulator](https://appshunter.io/ios/app/pt-ductulator/id6755953588) | — | Free | Productivity |
| [Digitales Lüftungsaufmaß](https://appshunter.io/ios/app/digitales-luftungsaufma/id1583576047) | 5.0 (1) | Free | Productivity |
| [HVAC Calculator Load Pro](https://appshunter.io/ios/app/hvac-calculator-load-pro/id6752215766) | 4.0 (1) | Free | Productivity |
| [Heating & Cooling HVAC Pro+](https://appshunter.io/ios/app/heating-and-cooling-hvac-pro-plus/id1356690113) | 4.8 (45) | Free | Productivity |
| [Ductulator - Duct Sizing](https://appshunter.io/ios/app/ductulator-duct-sizing/id1474939475) | 4.7 (317) | $3.99 | Productivity |

## More apps by Sachinbhai Surani

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All apps by Sachinbhai Surani: https://appshunter.io/developer/1838685550

## Related topics

[air duct calculator](https://appshunter.io/ios/topics/air-duct-calculator) · [duct sizing](https://appshunter.io/ios/topics/duct-sizing) · [hvac duct size calculator](https://appshunter.io/ios/topics/hvac-duct-size-calculator) · [duct calculator](https://appshunter.io/ios/topics/duct-calculator)

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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 2026-10-12.*