# Janus Calculator vs RPN

The clearest difference is price: Janus Calculator at Free against RPN's $4.99. Janus Calculator also leads on device support (3 vs 1). RPN's advantage is rating (4.3 vs 2.0) and update cadence (every 3 months vs every 45 months). On review sentiment, ads and in-app purchases there is nothing between them.

Janus Calculator is free to download; RPN costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

RPN holds the better App Store score, 4.3 against 2.0. That said, the two scores are not equally well evidenced: RPN has 6 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 83% of Janus Calculator's written reviews are positive against 90% of RPN's.

Janus Calculator ships an update every 45 months, RPN every 3 months. The most recent releases landed on November 1, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | Janus Calculator | RPN |
| --- | --- | --- |
| Price | **Free** | $4.99 |
| Rating | [2.0 (1 ratings)](https://appshunter.io/ios/app/janus-calculator/id373378721/reviews) | **[4.3 (6 ratings)](https://appshunter.io/ios/app/rpn-67-pro/id603103972/reviews)** |
| Number of ratings | 1 | **6** |
| Positive reviews | 83.3% of reviews | **90.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 45 months | **Every 3 months** |
| Monetization | **Free** | Paid |
| Size | 1 MB | 78 MB |
| Requires iOS | 26.2 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPad |
| Age rating | 4+ | 4+ |
| Developer | [Geoffrey Domm](https://appshunter.io/developer/373378724) | [CuVee Software](https://appshunter.io/developer/424873503) |

## What reviewers say

### Janus Calculator

[App page](https://appshunter.io/ios/app/janus-calculator/id373378721)

This app offers a unique dual-calculator interface, supporting both standard and Reverse Polish Notation. It features programmable functions, extensive scientific and financial tools, and includes physical constants and an advanced option calculator.

**Highlights:** Dual calculator interface (Standard and RPN), Programmable functions, Finance and scientific functions, Physical constants, Black-Scholes option calculator, Implied value calculation

**Features:** macOS Compatibility

**In-app purchases:** none


### RPN

[App page](https://appshunter.io/ios/app/rpn-67-pro/id603103972)

This app is a faithful simulation of a legendary 1970s programmable calculator, offering advanced features for scientists and engineers. It allows users to run existing programs, manage virtual program cards, and even print listings, all on their iPad.

**Highlights:** Virtual program and data cards, Virtual paper tape printer, Database-driven card manager, Save card collections to Mac/PC, Formatted program listings, Print listings via AirPrint, Live display of stack and registers

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Janus Calculator free?

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

### Is RPN free?

RPN costs $4.99, with no in-app purchases.

### Which has better reviews, Janus Calculator or RPN?

RPN is rated higher. Janus Calculator averages 2.0 out of 5 from 1 ratings, while RPN averages 4.3 from 6 ratings.

### Do Janus Calculator or RPN have ads?

Neither Janus Calculator nor RPN shows ads.

### Which is updated more often, Janus Calculator or RPN?

Janus Calculator ships an update every 45 months, and RPN every 3 months. Most recently, Janus Calculator was updated on November 1, 2026 and RPN on November 4, 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.*