iPhone Screenshots


RPN Calculator 48 is a polished RPN replacement for Apple's built-in calculator:

- Starts quickly
- Large buttons
- Easy-to-read display
- Same scientific functionality as Apple's calculator
- 100 entry stack (4 to 7 visible)
- 6 memory buttons (A-F)
- 50+ levels of undo/redo
- Saves state on exit

** Use swipe gestures to undo/redo operations!! **

The ergonomics (screen and keyboard layout) of RPN Calc. 48 were inspired by HP's outstanding 48-series calculator.

RPN Calc. 48 is made by the developer of tChess (the critically acclaimed iPhone chess game) and Learn Chess (the Apple Staff Favorite e-book).

What’s New

Version 1.0.5

- Native support for the iPhone 6 and 6 Plus screen resolutions
- Fixes an incompatibility with iOS 9

Ratings and Reviews

4.6 out of 5
34 Ratings
34 Ratings
MattEngineer ,


Most importantly, it doesn't do what you don't want to do. How novel!

I deleted my last RPN. Gave up. With that one they went thru great effort make it look EXACTLY like a 32s. Er uh- we aren't matching a set of seat cushions here. You needed a toothpick to hit each tiny little key. Also- who is going to do complex clacs on a hand held? If you're a student taking a test you can't. If you're a student at home you have your desktop or laptop. If you're an engineer, you're holding this thing in your had while the computer is doing the complicated stuff. Or you're at a job. You're going to solve a 3rd order poly equation out on a job holding this thing in your hand? No you go back to your car and use your laptop. Geeze! Don't app writers get out much?

Theses guys that designed this one kind of get it. A perfect product.

And you can set the keys to flash when you press them. That's the best idea I've seen in a long time. No looking back and forth to the screen to see if you pushed the right key.

And a settings window? Gee- why not make it like the 32s where you can't figure out anything without spending 30 min sorting thru a 200 page pdf copy of the manual? (written by the same guys that designed the program).

Thanks. You guys (the designers) made my week.

tommii3 ,

It just works

I bought my first iPhone--an iPhone SE--about two weeks ago. One of the first apps I downloaded was HP Prime. The buttons were so tiny, especially on this screen, that it was almost useless. So I tried using Apple's builtin calculator app. I didn't like it. At all.
RPN 48 is exactly what I was looking for: polished, functional, and practical. It's little things like switching the color scheme to your preferred 48 and flashing the buttons as you type out characters, that make this calculator go above and beyond. The developer could have just designed an also ran app that only included RPN, but he cared enough to go the extra mile. Thank you!
As a side note, I uninstalled the Apple calculator app, and now my wife doesn't know how use my phone as a calculator when she doesn't have hers!

Phil_Avenger ,

The Best RPN on iOS

Hands down the best calculator app for those biased to RPN. It has all the basic functions that you’d want to execute on your phone and nothing else to clutter the display. I really like the HUGE stack as well. The layout is clean and the color schemes add a nice little touch of flair. I can’t speak highly enough about this app. My only gripe is that you can fill the stack and it will prevent you from entering more numbers. This doesn’t come up often since the stack has to be around 100 entries, but I’d prefer if it would start overwriting the top of the stack as a new number is entered.


Tom Kerrigan
750.6 KB

Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© Tom Kerrigan


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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