# Fraction Calculator vs Opterra Cortex

The clearest difference is in-app purchases: Opterra Cortex at none against Fraction Calculator's 5. On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Fraction Calculator sells 5 in-app purchases, starting at $4.99 per month. Opterra Cortex asks for nothing beyond the download.

## The numbers

| Metric | Fraction Calculator | Opterra Cortex |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (157 ratings)](https://appshunter.io/ios/app/fraction-calculator/id1078884704/reviews)** | — |
| Number of ratings | **157** | — |
| Positive reviews | 75.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Monthly | — |
| Monetization | Free with in-app purchases | — |
| Size | 41 MB | 35 MB |
| Requires iOS | 16.4 | **16.0** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [xNeat.com](https://appshunter.io/developer/327498295) | [Evan Graven](https://appshunter.io/developer/1587270899) |

## What reviewers say

### Fraction Calculator

[App page](https://appshunter.io/ios/app/fraction-calculator/id1078884704)

This tool converts between decimals and fractions, and also handles unit conversions for construction and metric measurements. It offers an intuitive interface for calculations and editing, with advanced features available through upgrades.

**Highlights:** Decimal to fraction conversion, Fraction to decimal conversion, Unit conversion (feet, inches, metric), Simultaneous equation and result display, Advanced editing capabilities, Today Screen integration

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Fraction Calculator | $4.99 | per month |
| Fraction Calculator | $39.99 | per year |
| Fraction Calculator Pro | $0.99 | one-time |
| Fraction Calculator | $3.99 | one-time |
| Fraction Calculator Plus | $4.99 | one-time |

**What reviewers like**

- 👍 Intuitive and easy-to-use interface
- 🚀 Fast calculation performance
- 💡 Excellent for woodworking and construction projects
- 🎨 Clean, customizable design with multiple themes
- 📐 Handles fractions beautifully with imperial measurements

**What reviewers complain about**

- 💰 Extremely expensive subscription model
- 🔐 Paywall blocks most useful features in free version
- 😞 Recent update changed from free to paid model
- 🎯 Unclear which features require payment
- 🖱️ Small buttons prone to accidental clicks

**Reported bugs**

- App crashes on opening (iPad)
- Crashes when using plus buttons (iPad)
- Syntax errors during fraction calculations
- App closes immediately upon opening
- Unwanted decimal points in fraction results

**Requested features**

- Save calculations for later use
- Support for sixths and twelfths (for typography/design)
- Reorganizable or customizable unit lists
- Full fraction support on Apple Watch
- Free trial period before requiring subscription


### Opterra Cortex

[App page](https://appshunter.io/ios/app/opterra-cortex/id6760212456)

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

**In-app purchases:** none


## Frequently asked questions

### Is Fraction Calculator free?

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

### Is Opterra Cortex free?

Opterra Cortex is free to download, with no in-app purchases.

### Do Fraction Calculator or Opterra Cortex have ads?

Neither Fraction Calculator nor Opterra Cortex shows ads.

---

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