# Calx vs |RPN| Scientific Calculator

The clearest difference is rating: Calx at 5.0 against |RPN| Scientific Calculator's 2.3. Calx also leads on review sentiment (100% vs 60%) and iOS requirement (12.0 vs 16). |RPN| Scientific Calculator's advantage is update cadence (fortnightly vs every 24 months) and device support (4 vs 2). On price, ratings volume, ads and in-app purchases there is nothing between them.

Calx costs $0.99 and |RPN| Scientific Calculator $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Calx holds the better App Store score, 5.0 against 2.3. Both are backed by a comparable volume of ratings — 2 and 3 respectively. Written reviews point the same way: 100% of Calx's written reviews are positive against 60% of |RPN| Scientific Calculator's.

Calx ships an update every 24 months, |RPN| Scientific Calculator fortnightly. The most recent releases landed on August 12, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | Calx | |RPN| Scientific Calculator |
| --- | --- | --- |
| Price | $0.99 | $0.99 |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/calx-stack-calculator/id928929230/reviews)** | [2.3 (3 ratings)](https://appshunter.io/ios/app/rpn-scientific-calculator/id1069467997/reviews) |
| Number of ratings | 2 | **3** |
| Positive reviews | **100.0% of reviews** | 60.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 24 months | **Fortnightly** |
| Monetization | Paid | Paid |
| Size | 4 MB | 2 MB |
| Requires iOS | **12.0** | 16 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Daniel Clelland](https://appshunter.io/developer/912177584) | [Bradley Smith](https://appshunter.io/developer/1069467996) |

## What reviewers say

### Calx

[App page](https://appshunter.io/ios/app/calx-stack-calculator/id928929230)

This calculator app utilizes Reverse Polish Notation (RPN) for efficient calculations by manipulating numbers on a stack. It offers a guided tutorial, gestural interaction, multiple keypads with various functions, and customization options for fonts and colors.

**Highlights:** Reverse Polish Notation (RPN), Gestural interaction, Multiple keypads (basic, scientific, statistical), Customizable fonts and colors, Guided tutorial

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

**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 Calx free?

Calx costs $0.99, 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, Calx or |RPN| Scientific Calculator?

Calx is rated higher. Calx averages 5.0 out of 5 from 2 ratings, while |RPN| Scientific Calculator averages 2.3 from 3 ratings.

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

Neither Calx nor |RPN| Scientific Calculator shows ads.

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

Calx ships an update every 24 months, and |RPN| Scientific Calculator fortnightly. Most recently, Calx was updated on August 12, 2026 and |RPN| Scientific Calculator on September 22, 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.*