# MathU RPN Calc — user reviews > 65 indexed App Store user reviews of MathU RPN Calc by Creative Creek, LLC, rated 5.00/5 from 117 ratings. - Source: https://appshunter.io/ios/app/mathu-rpn-calc/id293653078/reviews - App overview in markdown: https://appshunter.io/ios/app/mathu-rpn-calc/id293653078.md - Rating breakdown: 5★ 113 · 4★ 3 · 3★ 1 · 2★ 0 · 1★ 0 ## Newest reviews (15 of 65) ### 5/5 — Awesome calculator! *2023-10-10* I use this calculator on a daily basis and absolutely love it. I have been a fan of HP calculators since the 80’s and glad I found this app a number of years ago. ### 5/5 — Superb *2022-06-10* I’ve used RPN since my first HP calculator 50 years ago. This app is a superb duplication of the original and looks just like the original keyboard. Perfect for all my scientific needs. ### 5/5 — Great calculator *2021-06-16* Been using for many years. Has surpassed my HP calculator for most purposes, though the H-P works great. RPN is the only way to go for engineering calculations. Learn it and you’ll never touch an arithmetic calculator again j ### 5/5 — My daily companion *2020-08-21* There is no single day when I use this calculator. Easy to handle and the same look and feel as my old HP calculator. Who is used to the unique UPN maths will find no better App. ### 5/5 — Wow, this nice calculator is still alive 👍🏻 *2020-07-03* Thank you very much. ### 5/5 — Love this calculator! *2020-07-02, version 3.1* This is my daily go-to calculator. It's also my absolute favorite HP emulator! It does everything I need from a calculator. Great combination of functions! Anyone who used the older vintage HPs will appreciate this calculator. Thank you Dr. Thompson for keeping this app current! ### 5/5 — Einwandfrei *2019-06-09* Sehr guter originalgetreuer HP Emulator. Ich verwende ihn seit Jahren gerne als Ersatz für meinen alten HP-15C, ### 5/5 — Really great RPN calculator *2018-08-07* I have been using this calculator for years and found it flawless for a RPN calculator. Reverse Polish Notation (RPN) calculators take less keystrokes than an algebraic version to complete a series of calculations. This calculator faithfully executes the HP look and feel for those wanting combined scientific and business functions in one app. I cannot praise this calculator enough. ### 5/5 — I love this calculator. *2014-11-07, version 3.0.1* For those of us that used RPN calculators from HP all through high school and college, this is a brilliant and familiar implementation of that model. ### 5/5 — Great workhorse of a calculator *2014-11-04, version 3.0.0* I have used this RPN calculator for many years and what can I say other than it works. The iPad version has some bugs with the settings and help that need to be resolved. ### 5/5 — Great but needs an update *2014-03-01, version 2.2.2* This is a great RPN calculator, I've used it for several years. However, it needs an update/fix - ever since I0S7 shipped you can not use it during a phone call - data input doesn't work. ### 5/5 — Outstanding *2012-11-14, version 2.2.2* I've tried many calculator apps and nothing comes close to this in terms of both appearance and function. Just buy it and stop looking. ### 5/5 — MathU *2012-06-08* The best I've seen and the only one I know of to have both Financial AND Scientific functions: engineers need to calculate "money" just like everyone, HP! Hope the pro (programmable) version is available soon! ### 5/5 — Best RPN Calculator *2011-10-11, version 2.2.2* I've been using this calculator on my Palm Pilot sense it came out. Best one around. I'm hoping they come out with MathUPro like they had for Palm. I really miss it. Used it all the time. Never has bugs and when you need help they respond quickly. Pro please!!! ### 5/5 — RPN business calc. *2011-07-21, version 2.2.2* Es la mejor calculadora del AppStore. Muy parecida a la 12c pero con un diseño mucho mas agradable y cómodo para iPhone. Yo no uso ninguna otra calculadora, ni virtual, ni física, ya que su profanación en RPN la hace mucho mas intuitiva que una convencional. ## Most critical reviews (10 lowest-rated) ### 1/5 — Top et pensive *2018-02-24* This appli is too expensive ! ### 1/5 — MathU RPN *2015-02-22* Diese APP ist nicht mehr Wert als 5 Euro. ### 2/5 — Help doesn't work *2014-10-28, version 2.2.2* Click help, app freezes, doesn't seem to work on iOS 8 ### 3/5 — Nothing like the Palm version - but nicely done anyway *2009-11-24* After using MathU Pro on the Palm, this version is pretty light. The Palm version allows configuring several different keyboards. I had one for units conversions, one for financial calcs, and several for engineering functions. And the 16 level stack could be viewed all at once. The RPN calculator that is offered by AL Software (a 41CX emulator) looks more interesting. I would give the Palm version five stars, so this one only gets three (but in fairness, I paid $45 for the Palm version). ### 3/5 — One big flaw *2009-02-15, version 0* Good calculator, but a deal breaker for me is that you can only view one line of the stack at a time. I feel like I'm working with blinders on! ### 4/5 — Best RPN calculator *2014-11-04* This is the best RPN calculator I've found. Have been using it for ages. There's an issue with the last update on my iPad mini: I'm not able to access the settings anymore. The dialog will pop up, but tapping settings (or Quick Reference) won't do anything. A very personal preference: turn off display of the financial registers or replace it with first 5 regular registers. I don't use the financial functions that frequently so it's just distracting. **Developer response:** The quick reference problem was fixed in 2020. Also, the financial registers can be used to display any numbers you want. Just use STO or RCL followed by the financial function key (like PMT) to store a number there. ### 4/5 — Great but needs IPhone 5 resolution support *2013-06-22, version 2.2.2* Love it but please update to use the additional real estate on the iPhone 5! ### 4/5 — This is the definitive RPN calculator for the iPhone/iTouch *2010-06-29, version 0* This the first application I sought when I purchased my iPod Touch! It's finally available, and I didn't hesitate to buy it. I have been a registered user of Clay's MathU Pro for PalmOS for many years and highly recommend this superior calculator. You will not be disappointed! ### 4/5 — Absolutely a "Must get" application *2010-02-13* If you use your Iphone as a calculator at all, even for the basic calculations, this is an awesome application. Obviously, its real benefit comes into play with some of the more complex calculations, but its ease of use and full range of useful features makes this one of the more useful apps I've downloaded yet. Another very nice, and almost genius aspect of this calculator is the portrait interpretation of the HP calculator. A lot of others offer the typical landscape orientation, but lets face it, the majority of the time you are holding your Iphone in a vertical orientation so its nice to have this powerful calculator available in that orientation. (It does also have the landscape orientation of the HP calculator if you rotate your Iphone, so that is like the icing on the cake!) :-) Well worth the price. ### 4/5 — Great app, great support. *2009-08-02, version 0* I have been using MathU pro on a Palm for over a decade. When they made it programable I put my HP 41c in storage. When they make the iPhone app programable I'll probably retire my Tungsten T3. This is a great app by a great company. They have never disappointed me. ## Most praised reviews (10 highest-rated) ### 5/5 — The best *2026-06-21* I love this app! Why can’t they make a similar app for Windows? ### 5/5 — This is the RPN Calculator to Get *2026-05-07* An old favorite, nay necessity, from my Palm days, I'm very happy to have this essential application for my iPod Touch. It works just like an old school HP Calculator, circa the HP-11 and 12 series, with the added bonus of an extended stack and scientific as well as financial functions. The original for the Palm was programable and there were several program suites that you can add on -- I hope these feature are forthcoming. However, given the excellent execution of this program, it's ease of use, and Creative Creek's very fine customer service, I do not hesitate giving this app 5 stars. Well done! ### 5/5 — Great RPN Calculator! *2026-04-25* Combines scientific and financial functions in the traditional HP style ### 5/5 — Best of the RPN calculators *2026-04-05, version 4.1.3* Does all the scientific calculations and most common financial ones too. Works exactly like the old HP RPN calculators with no quirks. Available on iOS, Android, and OS X. ### 5/5 — Love this calculator! *2026-02-17* This is my daily go-to calculator. It's also my absolute favorite HP emulator! It does everything I need from a calculator. Great combination of functions! Anyone who used the older vintage HPs will appreciate this calculator. Thank you Dr. Thompson for keeping this app current! ### 5/5 — 18 Years Using This Calculator *2026-01-31* I was surprised to see the subtle indication that my go to calculator app had been updated. It’s not the same as my collegiate HP-33E, but better. Do any other apps have this quality and longevity? I doubt it. Never had a single problem with it. Now that it’s also MacOS compatible I can finally put my favorite calculator on my desktop too. ### 5/5 — Absolutely the best *2025-08-25* I've tried several RPN calculator emulators for the iPhone, and this is hands-down the best. It recreates the functions and "feel" of an HP calculator, but doesn't waste space with stupid pictures of the edges of a physical calculator, etc. Worth much more than they charge... ### 5/5 — Wer den HP liebt *2024-04-13* Ich habe die App täglich in Benutzung und liebe sie einfach. Keine Probleme! ### 5/5 — Perfect RPN Calculator *2023-11-25* Originale Umsetzung der HP RPN-Rechner. Ich bin begeistert. Danke für den einmalig guten und schnellen Support. ### 5/5 — Love this calculator! *2023-10-26* This is my daily go-to calculator. It's also my absolute favorite HP emulator! It does everything I need from a calculator. Great combination of functions! Anyone who used the older vintage HPs will appreciate this calculator. Thank you Dr. Thompson for keeping this app current! --- *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 2026-09-05.*