# CaptiveAire Toolbox vs Construction Calc

The clearest difference is in-app purchases: CaptiveAire Toolbox at none against Construction Calc's 1. CaptiveAire Toolbox also leads on update cadence (every 6 days vs every 2 months) and iOS requirement (16.0 vs 18.0). On price, ads and device support there is nothing between them.

Both are free to download. Construction Calc sells 1 one-off in-app purchase. CaptiveAire Toolbox asks for nothing beyond the download.

CaptiveAire Toolbox ships an update every 6 days, Construction Calc every 2 months. The most recent releases landed on October 5, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | CaptiveAire Toolbox | Construction Calc |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/captiveaire-toolbox/id6765656560/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 6 days** | Every 2 months |
| Monetization | Free | — |
| Size | 71 MB | 15 MB |
| Requires iOS | **16.0** | 18.0 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [CaptiveAire Systems, Inc.](https://appshunter.io/developer/1896026735) | [Alona Nesterenko](https://appshunter.io/developer/1890650834) |

## What reviewers say

### CaptiveAire Toolbox

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

This app provides over 40 HVAC and building-systems engineering calculators. It's designed for field use, offering standard industry formulas for cooling, heating, ventilation, electrical sizing, and more. Access detailed formula definitions and reference data.

**Highlights:** 40+ HVAC engineering calculators, Cooling and heating load calculations, Ventilation and airflow tools, Electrical sizing and motor circuits, Duct and piping pressure drop, Reference data and psychrometric chart

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

**In-app purchases:** none


### Construction Calc

[App page](https://appshunter.io/ios/app/construction-calc-toolbox/id6792015651)

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Access | $7.99 | one-time |


## Frequently asked questions

### Is CaptiveAire Toolbox free?

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

### Is Construction Calc free?

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

### Do CaptiveAire Toolbox or Construction Calc have ads?

Neither CaptiveAire Toolbox nor Construction Calc shows ads.

### Which is updated more often, CaptiveAire Toolbox or Construction Calc?

CaptiveAire Toolbox ships an update every 6 days, and Construction Calc every 2 months. Most recently, CaptiveAire Toolbox was updated on October 5, 2026 and Construction Calc on October 11, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*