# HVAC Pipe Sizer vs Duct Calculator

The clearest difference is price: Duct Calculator at Free against HVAC Pipe Sizer's $4.99. Duct Calculator also leads on iOS requirement (15.6 vs 17.0). On update cadence, ads, in-app purchases and device support there is nothing between them.

Duct Calculator is free to download; HVAC Pipe Sizer costs $4.99 up front. HVAC Pipe Sizer sells 1 one-off in-app purchase and Duct Calculator sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

HVAC Pipe Sizer ships an update every 8 months, Duct Calculator every 10 months. The most recent releases landed on October 27, 2026 and October 26, 2026 respectively.

## The numbers

| Metric | HVAC Pipe Sizer | Duct Calculator |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | — | **[4.7 (3 ratings)](https://appshunter.io/ios/app/duct-calculator-hvac-sizing/id6756908372/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | 71.4% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 8 months** | Every 10 months |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 1 MB | 44 MB |
| Requires iOS | 17.0 | **15.6** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | +4 | 4+ |
| Developer | [Carmel Software Corporation](https://appshunter.io/developer/317970398) | [Sachinbhai Surani](https://appshunter.io/developer/1838685550) |

## What reviewers say

### HVAC Pipe Sizer

[App page](https://appshunter.io/ios/app/hvac-pipe-sizer-liquid/id325069065)

Calculate pipe sizes for liquid systems, including hot and chilled water. Input flow rate, head loss, diameter, or velocity to determine other properties. Supports various liquids, pipe materials, and fittings, with English or metric units.

**Highlights:** Liquid pipe sizing, Hydronic system calculations, Input flow, head loss, diameter, or velocity, Calculate fluid flow and head loss, Supports various liquids and pipe materials, English and metric unit options, Email results

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| HVAC Equipment Locator | $9.99 | one-time |


### 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 Pipe Sizer free?

HVAC Pipe Sizer costs $4.99, and also offers in-app purchases.

### Is Duct Calculator free?

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

### Do HVAC Pipe Sizer or Duct Calculator have ads?

Neither HVAC Pipe Sizer nor Duct Calculator shows ads.

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

HVAC Pipe Sizer ships an update every 8 months, and Duct Calculator every 10 months. Most recently, HVAC Pipe Sizer was updated on October 27, 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.*