# r.Calc > RPN calculator with a 100-position stack for daily calculations. (iPhone/iPad app by Nicolas Jorand.) - Source: https://appshunter.io/ios/app/rcalc/id291200623 (this page in markdown: same URL + `.md`) - Developer: [Nicolas Jorand](https://appshunter.io/developer/291200626) - Category: Utilities, Productivity - Price: $0.99 - Rating: 4.00/5 from 3 App Store ratings · 4 written reviews indexed - Age rating: 4+ - Requires: iOS 2.2.1 · 0 MB - Languages: American English, French (France), European Spanish - Released: 2024-12-04 - Data updated: 2026-06-10 - Monetization: paid - User reviews in markdown: https://appshunter.io/ios/app/rcalc/id291200623/reviews.md ## What is r.Calc? This classic RPN (Reverse Polish Notation) calculator is a simple calculator for daily uses. The calculator features a four visible level stack, the total stack size has a total of hundred positions. A progress bar on the top of the screen shows you how the stack is full. For now the implemented operations are; Plus, Minus, Multiply, Divide, Opposite, Inverse. Other facilities like swap the first two number in the stack and recall from the last operation the two arguments should simplify the life. All keyboard errors are notified by a vibration. ## Key features - Reverse Polish Notation (RPN) input - Four visible stack levels - 100-position stack capacity - Progress bar for stack fullness - Basic arithmetic operations - Stack swap and recall functions - Vibration feedback for errors ## Recent user reviews (4 of 4) All indexed reviews: https://appshunter.io/ios/app/rcalc/id291200623/reviews.md ### 5/5 — Excellent RPN calculator *2009-04-07, version 0* I usually dont write reviews, but this is one of the most stable apps i own in the iphone. I bought this app a long time ago but Like others said, it does what it describes very well. Worth the 99 cents very good, nice job. ### 5/5 — Does what it says, and does it well. *2009-03-01, version 0* As I summarized in the title, it is a simple, straight forward RPN calculator. I've been using it for about 5 months now anytime i need a calculator on my phone, and it has held up to anything I have put it through. For those who don't know how to use RPN calculators, LEARN... It is a very useful way to do math. Once you know what is going on, you can work far faster, with far less re-inputing numbers. All in all I think this is a great little app. ### 5/5 — Awesome app *2008-12-28, version 0* Love the 4 line display with an additional editing line which essentially turns this into a 5 line display. Can't wait to see future updates and where the developer can take this ### 4/5 — Excellent for basic RPN use. *2008-11-26, version 0* This is a fast, responsive RPN calculator for everyday use. Just the basic math operations without the clatter of other RPN calculators. As a result it loads very fast ready for use. And the vertical orientation, more natural for the iPod touch, is a definite plus. This is now my default calculator. My only recommendation is to add a key to empty the entire stack with one keypress, there is room next to the "D" key. Hopefully in the next update. Good job! ## Frequently asked questions about r.Calc ### What is RPN and how does r.Calc use it? RPN, or Reverse Polish Notation, is a method of calculation where operators follow operands. r.Calc uses this notation, meaning you enter numbers first, then the operation to perform on them. ### What are the basic operations supported by r.Calc? r.Calc supports fundamental arithmetic operations including Plus, Minus, Multiply, and Divide. It also includes functions for Opposite and Inverse. ### How large is the stack in r.Calc and how is it visualized? The calculator features a four-level visible stack with a total capacity of 100 positions. A progress bar at the top of the screen visually indicates how full the stack is. ### Does r.Calc have any features to simplify calculations? Yes, r.Calc includes features to simplify calculations. You can swap the first two numbers on the stack and recall the two arguments from the last operation. ### How does r.Calc notify users of errors? All keyboard errors in r.Calc are notified by a vibration, providing immediate feedback to the user. ### What devices is r.Calc compatible with? r.Calc is designed for Apple devices, specifically supporting iPhone and iPod. ### How much does r.Calc cost and is it ad-free? r.Calc is a paid application priced at $0.99. It is ad-free, as indicated by its monetization model and the absence of ad-related flags. ### When was r.Calc last updated and what is its current version? r.Calc was last updated on December 4, 2024, with its latest version being 1.1. This indicates recent development and support from the developer. ## Version history (last 2 releases) ### 1.1 — 2024-12-04 - Bug Fixes. - Add Clear All Stack. - Add French and Spanish Localization. ### 1.0 — 2008-09-21 No release notes. ## Apps similar to r.Calc | App | Rating | Price | Category | | --- | --- | --- | --- | | [Plus42](https://appshunter.io/ios/app/plus42/id1597963622) | 4.9 (76) | $9.99 | Utilities | | [SwiftRPN](https://appshunter.io/ios/app/swiftrpn/id6470951024) | — | Free | Utilities | | [Dozecal](https://appshunter.io/ios/app/dozecal/id1521160089) | 4.0 (4) | Free | Utilities | | [GO-21 SciRPN](https://appshunter.io/ios/app/go-21-scirpn/id327651563) | 4.9 (12) | $2.99 | Utilities | | [Complex RPN Calculator](https://appshunter.io/ios/app/complex-rpn-calculator/id291826330) | 3.8 (22) | Free | Utilities | | [bcRPN](https://appshunter.io/ios/app/bcrpn/id1614744829) | 4.8 (4) | Free | Utilities | --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*