iPhone Screenshots


RPN Calculator 48 is a polished RPN replacement for Apple's calculator app:

- Same scientific functionality as Apple's calculator app*
- Use swipe gestures to undo and redo operations!
- Starts quickly
- Large buttons
- Easy-to-read display
- 100 entry stack
- 6 memory buttons (A-F)
- 50+ levels of undo/redo
- Saves state on exit

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

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

* This app is not an HP 48 emulator.

What’s New

Version 1.0.7

- The "LOGx" button was incorrectly labeled "LOGy". Fixed.

Ratings and Reviews

4.7 out of 5
111 Ratings

111 Ratings

Danilo720 ,

Great RPN Calculator Inspired by the 48s

The app focuses on the essential scientific operations from the 48 series (essentially the scientific calculations that the calculator that comes with the phone can perform). Really clever simplification, fast, functional and graphically pleasant. Read carefully the description from the developer and there will be no disappointments.

Nitpicking: I probably overused the “DEL” button on the 48G to clear the stack, so using the left arrow to access this functionality irritates a bit (I really miss a direct button for that); having a dedicated button for “settings” replacing the “ON” button on the 48s seems a waste of one the most accessible buttons in this layout; “2nd” could be optionally a permanent toggle (and calling it “NXT”, as the calculators, would be appropriate and/or clearer); would like to see a square root symbol that actually encompasses the “x” - the developer probably tried to avoid adding a figure and use actual text characters for speed, which is understandable.

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!

App Privacy

The developer, Tom Kerrigan, has not provided details about its privacy practices and handling of data to Apple. For more information, see the developer's privacy policy.

No Details Provided

The developer will be required to provide privacy details when they submit their next app update.


Tom Kerrigan
1.2 MB

Requires iOS 13.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating


  • Family Sharing

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

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