# RPN Calc vs RPNPro

The clearest difference is price: RPNPro at Free against RPN Calc's $0.99. RPNPro also leads on rating (5.0 vs 4.0) and review sentiment (50% vs 38%). RPN Calc's advantage is update cadence (every 3 months vs every 37 months) and ratings volume (6 vs 1). On ads, in-app purchases, monetization model and device support there is nothing between them.

RPNPro is free to download; RPN Calc costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

RPNPro holds the better App Store score, 5.0 against 4.0. That said, the two scores are not equally well evidenced: RPN Calc has 6 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 38% of RPN Calc's written reviews are positive against 50% of RPNPro's.

RPN Calc ships an update every 3 months, RPNPro every 37 months. The most recent releases landed on October 24, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | RPN Calc | RPNPro |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [4.0 (6 ratings)](https://appshunter.io/ios/app/rpn-calc/id285002799/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rpnpro/id603155368/reviews)** |
| Number of ratings | **6** | 1 |
| Positive reviews | 37.9% of reviews | **50.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 37 months |
| Monetization | Free | Free |
| Size | 3 MB | 1 MB |
| Requires iOS | 16.0 | **9.1** |
| Devices | iPhone, iPad, Apple Watch | iPhone, iPad, iPod |
| Age rating | +4 | 4+ |
| Developer | [James Mattis](https://appshunter.io/developer/285002802) | [Felix Meier](https://appshunter.io/developer/603155771) |

## What reviewers say

### RPN Calc

[App page](https://appshunter.io/ios/app/rpn-calc/id285002799)

This app provides a straightforward reverse Polish notation (RPN) calculator experience, inspired by classic HP models. It offers a clean interface with large buttons for quick calculations on iPhone, iPad, and Apple Watch, along with a convenient Today Extension for immediate access.

**Highlights:** Reverse Polish Notation (RPN) input, Clean, simple interface, Large, easy-to-press buttons, iPhone, iPad, and Apple Watch support, Today Extension for quick access

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases:** none


### RPNPro

[App page](https://appshunter.io/ios/app/rpnpro/id603155368)

This calculator utilizes Reverse Polish Notation (RPN) for input, mirroring the functionality of classic HP calculators. It features a four-level stack with X, Y, Z, and T registers, displaying the X register in decimal, hexadecimal, and binary.

**Highlights:** Reverse Polish Notation (RPN) input, Four-level stack (X, Y, Z, T registers), Decimal, hexadecimal, and binary display, Modeled after HP calculators, Designed for software engineers

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is RPN Calc free?

RPN Calc costs $0.99, with no in-app purchases.

### Is RPNPro free?

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

### Which has better reviews, RPN Calc or RPNPro?

RPNPro is rated higher. RPN Calc averages 4.0 out of 5 from 6 ratings, while RPNPro averages 5.0 from 1 ratings.

### Do RPN Calc or RPNPro have ads?

Neither RPN Calc nor RPNPro shows ads.

### Which is updated more often, RPN Calc or RPNPro?

RPN Calc ships an update every 3 months, and RPNPro every 37 months. Most recently, RPN Calc was updated on October 24, 2026 and RPNPro on October 14, 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.*