# RPN Memory Calculator — RPN Multi Function Calculator

> Simple RPN calculator with memory, unit conversions, and persistent state. (iPhone/iPad app by Neverest Limited.)

- Source: https://appshunter.io/ios/app/rpn-memory-calculator/id1398878075 (this page in markdown: same URL + `.md`)
- Developer: [Neverest Limited](https://appshunter.io/developer/1360645388)
- Category: Education, Productivity
- Price: Free with in-app purchases
- Age rating: 4+
- Requires: iOS 11.3 · 8 MB
- Languages: American English
- Released: 2018-07-24
- Data updated: 2026-06-01
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/rpn-memory-calculator/id1398878075/reviews.md

## What is RPN Memory Calculator?

RPN Memory Calculator is a simple to use reverse polish notation calculator with seven functions and memory operations including a memory value display and three visible registers. This is not intended to be a full scientific function calculator, it is a handy implementation of basic calculator operations using RPN.

The calculator also integrates unit conversions, so you can convert the value in the x register. This allows you to choose a type (Speed, Mass, Temperature, Pressure etc) and then pick a from and to type. The converted number can either be accepted back into the x register, or discarded.

The calculator remembers state so that calculations you have been working on, with results stored in either the memory field or any of the registers, will still be present when re-open the app any time in the future. All registers, even the hidden ones above z are stored.

## Key features

- Reverse Polish Notation (RPN) input
- Seven core calculator functions
- Memory operations
- Integrated unit conversions (Speed, Mass, Temperature, Pressure)
- Persistent state saving
- Three visible registers

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Calculator Unit Conversions | $0.99 | one-time |


## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/rpn-memory-calculator/id1398878075/reviews.md

### 2/5 — Limited

*2021-08-25*

An uninviting interface with little appeal, except that it's free and has no advertising. Hmm, actually, I'm going to add a star for that!
The flat colour is not a problem but I don't get why the operands do not have the standard appearance. What's wrong with the simple x / + - ? Even if intended to educate someone unfamiliar with RPN, surely it's unnecessary to have these keys denoted as y+x, etc.?

I'm giving two stars for the fact that it has no advertising and is free. That much is to be commended; but please rethink the interface.

## Frequently asked questions about RPN Memory Calculator

### What is RPN Memory Calculator?

RPN Memory Calculator is a free application designed for iOS devices that offers a reverse Polish notation (RPN) calculator with seven functions and memory operations. It also includes unit conversions and saves your calculation state.

### Does RPN Memory Calculator have ads?

No, RPN Memory Calculator is ad-free, providing an uninterrupted user experience for calculations and unit conversions.

### What devices is RPN Memory Calculator compatible with?

RPN Memory Calculator is compatible with iPhones, iPads, and iPods, running on iOS.

### How often is RPN Memory Calculator updated?

The app was last updated on December 26, 2022, with version 1.3.4. While specific update frequency isn't detailed, this indicates ongoing support.

### What kind of unit conversions does RPN Memory Calculator offer?

RPN Memory Calculator supports unit conversions for categories such as Speed, Mass, Temperature, and Pressure, allowing you to convert values directly within the x register.

### Is RPN Memory Calculator suitable for advanced scientific calculations?

No, RPN Memory Calculator is intended as a handy implementation of basic calculator operations using RPN and is not a full scientific function calculator.

### Does RPN Memory Calculator remember my calculations?

Yes, RPN Memory Calculator remembers its state, meaning calculations, results, and values stored in memory or registers will be present when you re-open the app.

### What is the age rating for RPN Memory Calculator?

RPN Memory Calculator has an age rating of 4+, making it suitable for a wide range of users.

## Version history (last 5 releases)

### 1.3.4 — 2022-12-26

Fixes font size irregularities in some iPhone mini models.

### 1.3.3 — 2022-11-06

Fixes button positioning issues seen on some recent iPhones.

### 1.3.2 — 2021-05-27

Support iPad split screen mode and minor corrections to layouts for 12 iPhones

### 1.3.1 — 2020-11-25

Updates to button positioning to improve the look on new iPhone (12) models

### 1.3.0 — 2020-03-20

Following requests from App users we have changed the purpose of the M+x and M-x buttons. These no longer operate on the memory value, those functions will need to be applied to the x register and then the memory value can be updated using M=x. Removing the M+x and M-x buttons has allowed us to add two new buttons: 

nth Root (x√y) - this button  takes the nth root of the y register, with n being the x register. We have removed the square root button, you can do a a square root of the y register by pressing the x√y button after entering a 2 into the x register. If you prefer to carry on using a regular square root, without a enter followed by entering 2 into the x register, a long press on x√y will toggle its meaning back to square root. Another long press toggles it back, so you can choose whatever mode you prefer as an when you like.

y to the power of x (y^x) - this button raises the value in the y register to the x register power. As above, this button can be toggled to a convenient square x (sq x) button with a long press.

last x - this new button is a convenience button: it does an enter (shifting x register into y, y into x, and so on) and then places the previous value of x prior to the last calculation back into the x register.

Finally, the locations of the π and 1/x buttons have moved.

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## More apps by Neverest Limited

- [NASA Navtex Viewer](https://appshunter.io/ios/app/nasa-navtex-viewer/id1360645389)
- [NASA Battery Viewer](https://appshunter.io/ios/app/nasa-battery-viewer/id1441904780)

All apps by Neverest Limited: https://appshunter.io/developer/1360645388

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*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 2026-06-01.*