# RPNPro vs |RPN| Scientific Calculator

The clearest difference is price: RPNPro at Free against |RPN| Scientific Calculator's $0.99. RPNPro also leads on rating (5.0 vs 2.3) and iOS requirement (9.1 vs 16). |RPN| Scientific Calculator's advantage is update cadence (fortnightly vs every 37 months) and review sentiment (60% vs 50%). On ads, in-app purchases and device support there is nothing between them.

RPNPro is free to download; |RPN| Scientific Calculator 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 2.3. Both are backed by a comparable volume of ratings — 1 and 3 respectively. Written reviews complicate that: 50% of RPNPro's written reviews are positive against 60% of |RPN| Scientific Calculator's, so the app with the better star average is not the one people write more warmly about.

RPNPro ships an update every 37 months, |RPN| Scientific Calculator fortnightly. The most recent releases landed on October 14, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | RPNPro | |RPN| Scientific Calculator |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rpnpro/id603155368/reviews)** | [2.3 (3 ratings)](https://appshunter.io/ios/app/rpn-scientific-calculator/id1069467997/reviews) |
| Number of ratings | 1 | **3** |
| Positive reviews | 50.0% of reviews | **60.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 37 months | **Fortnightly** |
| Monetization | **Free** | Paid |
| Size | 1 MB | 2 MB |
| Requires iOS | **9.1** | 16 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Felix Meier](https://appshunter.io/developer/603155771) | [Bradley Smith](https://appshunter.io/developer/1069467996) |

## What reviewers say

### 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


### |RPN| Scientific Calculator

[App page](https://appshunter.io/ios/app/rpn-scientific-calculator/id1069467997)

This calculator app uses Reverse Polish Notation for powerful calculations. It offers customizable color schemes, layouts, and online help, designed for flexibility and usability. All features are unlocked with a one-time purchase.

**Highlights:** Reverse Polish Notation (RPN), Viewable stack, Selectable portrait/landscape layouts, Customizable color schemes, Online visual help, No ads or in-app purchases

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is RPNPro free?

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

### Is |RPN| Scientific Calculator free?

|RPN| Scientific Calculator costs $0.99, with no in-app purchases.

### Which has better reviews, RPNPro or |RPN| Scientific Calculator?

RPNPro is rated higher. RPNPro averages 5.0 out of 5 from 1 ratings, while |RPN| Scientific Calculator averages 2.3 from 3 ratings.

### Do RPNPro or |RPN| Scientific Calculator have ads?

Neither RPNPro nor |RPN| Scientific Calculator shows ads.

### Which is updated more often, RPNPro or |RPN| Scientific Calculator?

RPNPro ships an update every 37 months, and |RPN| Scientific Calculator fortnightly. Most recently, RPNPro was updated on October 14, 2026 and |RPN| Scientific Calculator on October 24, 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.*