iPhone Screenshots


Reverse Polish Notation ("RPN") is an alternative way to complete calculations. Many find it to be more intuitive and user-friendly than the "normal" way of using a calculator. RPN works entering numbers first and then the operator (i.e. 53 47 + will give you 53 + 47 = 100).

This calculator takes inspiration from the standard Apple iPhone calculator and modifies it into user-friendly RPN calculator.

Please note the important following functions / instructions:

- Pressing down on a button for more than 0.3 seconds lets you access its alternate function key. This saves us from having to press function and then the key (which is how other calculators normally work).

- Tap on the main number display screen (x-register) to delete digits one at a time

- Tap once, tap twice or tap thrice on the stack register display in the top right corner to recall values stored in the stack register

- Tap the white number in the top left corner (y-register value) to swap it with what is stored in the main display (x-register)

- Tap the grey text in the top left corner to reverse the last calculation

- To store and recall numbers you need to long press the zero and decimal keys respectively and then select a register from 1-9 (by pressing the respective digits) at the same time

- Consecutive presses of the CLR key clears the stack and a long press will clear the full stack

- This calculator has an unlimited stack register. Also, I didn't put many scientific functions into the calculator because our focus is on usability. You are probably better off using a computer if you are thinking of doing long complex calculations in a calculator!

Please enjoy and leave a review if you like the calculator. It will always be free to use, but the more downloads and reviews will help me in marketing future apps - so recommend it to your friends!

What’s New

Version 1.25

Unfortunately, minor bug had to be corrected. Apologies for the multiple versions - hopefully this should be the last

Ratings and Reviews

5.0 out of 5
1 Rating

1 Rating


Ashok Khanna
7.7 MB

Requires iOS 12.1 or later. Compatible with iPhone, iPad and iPod touch.



Age Rating


  • Family Sharing

    Up to six family members will be able to use this app with Family Sharing enabled.

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