# Ductulator vs CaptiveAire Toolbox

The clearest difference is in-app purchases: CaptiveAire Toolbox at none against Ductulator's 2. CaptiveAire Toolbox also leads on rating (5.0 vs 4.5) and update cadence (every 8 days vs every 8 months). Ductulator's advantage is ratings volume (36 vs 1). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Ductulator sells 2 in-app purchases, starting at $4.99 per month. CaptiveAire Toolbox asks for nothing beyond the download.

CaptiveAire Toolbox holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Ductulator has 36 ratings behind it against 1, so its average is the more settled of the two.

Ductulator ships an update every 8 months, CaptiveAire Toolbox every 8 days. Both last shipped on November 9, 2026.

## The numbers

| Metric | Ductulator | CaptiveAire Toolbox |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.5 (36 ratings)](https://appshunter.io/ios/app/ductulator-duct-calculator/id6757307937/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/captiveaire-toolbox/id6765656560/reviews)** |
| Number of ratings | **36** | 1 |
| Positive reviews | 75.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 8 months | **Every 8 days** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 42 MB | 71 MB |
| Requires iOS | 17.0 | **16.0** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Mikhail Nikitin](https://appshunter.io/developer/1826368571) | [CaptiveAire Systems, Inc.](https://appshunter.io/developer/1896026735) |

## What reviewers say

### Ductulator

[App page](https://appshunter.io/ios/app/ductulator-duct-calculator/id6757307937)

This app provides professional HVAC duct sizing and psychrometric calculations in a single tool. It offers detailed calculations for various duct types and materials, along with comprehensive humid air property analysis. Designed for HVAC professionals, it replaces traditional ductulators with accurate digital functionality.

**Highlights:** Duct sizing for round, rectangular, and flexible ducts, Fittings pressure drop calculation, Psychrometric analysis with interactive chart, Supports Imperial and Metric units, Pre-configured velocity limits for application types, Real-time validation warnings

**Features:** Family Sharing, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| premium | $4.99 | per month |
| premium | $29.99 | per year |


### CaptiveAire Toolbox

[App page](https://appshunter.io/ios/app/captiveaire-toolbox/id6765656560)

This app provides over 40 HVAC and building-systems engineering calculators, offering quick field calculations for engineers, contractors, and technicians. It covers cooling, heating, ventilation, electrical sizing, piping, and valve sizing, all based on standard industry references.

**Highlights:** 40+ HVAC engineering calculators, Cooling and heating load calculations, Ventilation and airflow analysis, Electrical sizing tools, Piping and structural calculations, Valve and flow sizing, Reference data and psychrometric chart

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

**In-app purchases:** none


## Frequently asked questions

### Is Ductulator free?

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

### Is CaptiveAire Toolbox free?

CaptiveAire Toolbox is free to download, with no in-app purchases.

### Which has better reviews, Ductulator or CaptiveAire Toolbox?

CaptiveAire Toolbox is rated higher. Ductulator averages 4.5 out of 5 from 36 ratings, while CaptiveAire Toolbox averages 5.0 from 1 ratings.

### Do Ductulator or CaptiveAire Toolbox have ads?

Neither Ductulator nor CaptiveAire Toolbox shows ads.

### Which is updated more often, Ductulator or CaptiveAire Toolbox?

Ductulator ships an update every 8 months, and CaptiveAire Toolbox every 8 days. Most recently, Ductulator was updated on November 9, 2026 and CaptiveAire Toolbox on November 9, 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.*