# Calca vs RPN

The clearest difference is price: RPN at $1.99 against Calca's $9.99. RPN also leads on in-app purchases (none vs 2) and rating (5.0 vs 4.5). Calca's advantage is ratings volume (157 vs 7). On ads and device support there is nothing between them.

Calca costs $9.99 and RPN $1.99 up front. Calca sells 2 one-off in-app purchases. RPN asks for nothing beyond the download.

RPN holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Calca has 157 ratings behind it against 7, so its average is the more settled of the two. Written reviews point the same way: 76% of Calca's written reviews are positive against 100% of RPN's.

Calca ships an update every 5 months, RPN every 2 months. The most recent releases landed on October 26, 2026 and October 20, 2026 respectively.

## The numbers

| Metric | Calca | RPN |
| --- | --- | --- |
| Price | $9.99 | **$1.99** |
| Rating | [4.5 (157 ratings)](https://appshunter.io/ios/app/calca/id635757879/reviews) | **[5.0 (7 ratings)](https://appshunter.io/ios/app/rpn-38-cx/id1082636662/reviews)** |
| Number of ratings | **157** | 7 |
| Positive reviews | 76.5% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | **Free with in-app purchases** | Paid |
| Size | 78 MB | 12 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Krueger Systems, Inc.](https://appshunter.io/developer/299293363) | [CuVee Software](https://appshunter.io/developer/424873503) |

## What reviewers say

### Calca

[App page](https://appshunter.io/ios/app/calca/id635757879)

This app is an advanced symbolic calculator and text editor. It solves equations, simplifies expressions, and allows you to explain your work alongside calculations. Calculations update instantly as you type, and all data is stored as plain text for easy sharing and device syncing.

**Highlights:** Symbolic calculation, Equation solving, Expression simplification, Markdown text editor, Real-time updates, Unit and currency conversion, Matrix operations

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 6-Month Optional Patronage | $4.99 | one-time |
| 12-Month Optional Patronage | $7.99 | one-time |

**What reviewers like**

- 💡 Unique blend of text editor and calculator
- 📝 Markdown support for documentation
- 🔄 Dynamic recalculation of all values
- ⚙️ Powerful mathematical and algebraic capabilities
- 📊 Unit conversion and unit-aware calculations

**What reviewers complain about**

- 🐛 Magic Keyboard input bugs on iPad
- ⚠️ Appears abandoned or poorly maintained
- 🐛 Text selection issues with external keyboards
- 📱 iPad landscape mode problems
- 🐛 Cursor jumping and screen jumping during editing

**Reported bugs**

- Magic Keyboard causes number input to overwrite instead of append
- Text selection before numbers triggers increment/decrement instead of selecting
- Cursor jumps forward and backward with external keyboards
- iPad Pro keyboard truncation in portrait mode
- Arrow key (=>) doesn't work in landscape mode

**Requested features**

- Files app and document browser integration
- Dropbox and Google Drive support
- Date calculation functionality
- Looping and iteration support
- User-defined function storage in separate files


### RPN

[App page](https://appshunter.io/ios/app/rpn-38-cx/id1082636662)

This app is a photo-realistic simulation of a classic Hewlett-Packard programmable business calculator. It offers advanced programming features, extensive register memory, and a library of pre-installed programs for various financial and statistical calculations.

**Highlights:** Photo-realistic look-and-feel, Programmable with subroutines and flags, 20 registers with unlimited store/recall, Indirect register addressing, Program library and sharing, Financial and statistical functions, Date and calendar calculations

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Calca free?

Calca costs $9.99, and also offers in-app purchases.

### Is RPN free?

RPN costs $1.99, with no in-app purchases.

### Which has better reviews, Calca or RPN?

RPN is rated higher. Calca averages 4.5 out of 5 from 157 ratings, while RPN averages 5.0 from 7 ratings.

### Do Calca or RPN have ads?

Neither Calca nor RPN shows ads.

### Which is updated more often, Calca or RPN?

Calca ships an update every 5 months, and RPN every 2 months. Most recently, Calca was updated on October 26, 2026 and RPN on October 20, 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.*