# RPN 28x Calc vs WP 31s

The clearest difference is price: WP 31s at Free against RPN 28x Calc's $6.99. RPN 28x Calc's advantage is update cadence (every 2 months vs every 10 months). On rating, review sentiment, ratings volume and ads there is nothing between them.

WP 31s is free to download; RPN 28x Calc costs $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for RPN 28x Calc against 4.9 for WP 31s. Both are backed by a comparable volume of ratings — 34 and 15 respectively. Written reviews are what separate them: 97% of RPN 28x Calc's written reviews are positive against 100% of WP 31s's.

RPN 28x Calc ships an update every 2 months, WP 31s every 10 months. The most recent releases landed on November 6, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | RPN 28x Calc | WP 31s |
| --- | --- | --- |
| Price | $6.99 | **Free** |
| Rating | **[5.0 (34 ratings)](https://appshunter.io/ios/app/rpn-28x-calc/id529927583/reviews)** | [4.9 (15 ratings)](https://appshunter.io/ios/app/wp-31s/id973621300/reviews) |
| Number of ratings | **34** | 15 |
| Positive reviews | 97.1% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 10 months |
| Monetization | Paid | **Free** |
| Size | 3 MB | 16 MB |
| Requires iOS | 12.4 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [tredje design](https://appshunter.io/developer/495557933) | [Pascal Meheut](https://appshunter.io/developer/620255097) |

## What reviewers say

### RPN 28x Calc

[App page](https://appshunter.io/ios/app/rpn-28x-calc/id529927583)

A programmable scientific calculator offering a classic aesthetic with modern functionality. It features a dynamic stack display, customizable buttons, and support for multiple data types, making complex calculations intuitive and accessible.

**Highlights:** Reverse Polish Notation (RPN) input, Dynamic stack display with scrolling, Customizable buttons and programming, Support for multiple data types (real, complex, binary, lists, etc.), 147 scientific units and physical constants, Interactive program debugging, Units and log viewers

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

**In-app purchases:** none


### WP 31s

[App page](https://appshunter.io/ios/app/wp-31s/id973621300)

This app emulates a classic RPN scientific calculator, offering a rich function set for daily use with a simplified interface. It's based on the more complex WP 34s but is designed for easier operation.

**Highlights:** RPN scientific calculator emulation, Rich function set, Simplified, less cluttered keyboard, Based on WP 34s, Available on iOS

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is RPN 28x Calc free?

RPN 28x Calc costs $6.99, with no in-app purchases.

### Is WP 31s free?

WP 31s is free to download, with no in-app purchases.

### Which has better reviews, RPN 28x Calc or WP 31s?

RPN 28x Calc is rated higher. RPN 28x Calc averages 5.0 out of 5 from 34 ratings, while WP 31s averages 4.9 from 15 ratings.

### Do RPN 28x Calc or WP 31s have ads?

Neither RPN 28x Calc nor WP 31s shows ads.

### Which is updated more often, RPN 28x Calc or WP 31s?

RPN 28x Calc ships an update every 2 months, and WP 31s every 10 months. Most recently, RPN 28x Calc was updated on November 6, 2026 and WP 31s on November 2, 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.*