# Calc Engine vs STRUCT Construction Calculator

The clearest difference is in-app purchases: STRUCT Construction Calculator at none against Calc Engine's 1. STRUCT Construction Calculator also leads on iOS requirement (13.0 vs 18). Calc Engine's advantage is update cadence (daily vs every 4 months) and device support (4 vs 2). On price and ads there is nothing between them.

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

Calc Engine ships an update daily, STRUCT Construction Calculator every 4 months. The most recent releases landed on August 31, 2026 and September 9, 2026 respectively.

## The numbers

| Metric | Calc Engine | STRUCT Construction Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/calc-engine/id1061766849/reviews)** | — |
| Number of ratings | **4** | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Daily** | Every 4 months |
| Monetization | Free | — |
| Size | 17 MB | 16 MB |
| Requires iOS | 18 | **13.0** |
| Devices | **iPhone, iPad, Mac, Apple Watch** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [VersaEdge Software, LLC](https://appshunter.io/developer/301294952) | [MOBILEXAPPS MB](https://appshunter.io/developer/1685170475) |

## What reviewers say

### Calc Engine

[App page](https://appshunter.io/ios/app/calc-engine/id1061766849)

A highly customizable calculator with advanced features like graphing, equation solving, and unit conversion. Design your own keyboards and functions to streamline your workflow across Apple devices.

**Highlights:** Customizable keyboard layouts, User-defined functions and constants, Live equation graphing, Equation solving, Extensive unit conversions, Programmer mode (hex, binary, octal), Cross-device syncing

**Features:** Family Sharing, Apple Watch app

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Calc Engine+ | $9.99 | one-time |


### STRUCT Construction Calculator

[App page](https://appshunter.io/ios/app/struct-construction-calculator/id6758335610)

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

**In-app purchases:** none


## Frequently asked questions

### Is Calc Engine free?

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

### Is STRUCT Construction Calculator free?

STRUCT Construction Calculator is free to download, with no in-app purchases.

### Do Calc Engine or STRUCT Construction Calculator have ads?

Neither Calc Engine nor STRUCT Construction Calculator shows ads.

### Which is updated more often, Calc Engine or STRUCT Construction Calculator?

Calc Engine ships an update daily, and STRUCT Construction Calculator every 4 months. Most recently, Calc Engine was updated on August 31, 2026 and STRUCT Construction Calculator on September 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.*