# Calculator12 RPN

> Emulates a popular financial calculator with modern cash flow and reporting features. (iPhone/iPad app by Stone Meadow Development LLC.)

- Source: https://appshunter.io/ios/app/calculator12-rpn/id286506398 (this page in markdown: same URL + `.md`)
- Developer: [Stone Meadow Development LLC](https://appshunter.io/developer/286506401)
- Category: Finance, Business
- Price: $1.99
- Rating: 4.43/5 from 7 App Store ratings · 31 written reviews indexed
- Age rating: 4+
- Requires: iOS 8.0 · 20 MB
- Languages: English, German, Portuguese, Spanish
- Released: 2019-02-12
- Data updated: 2026-06-10
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/calculator12-rpn/id286506398/reviews.md

## What is Calculator12 RPN?

More than 30 years ago we saw the birth of the most popular financial calculator ever created--you probably had one (and probably still do!).

Calculator12 puts a rock solid emulation of that calculator on your iPhone, iPod touch and iPad, whether you need it for school or are looking to retire old faithful. What you get is true (albeit non-programmable) emulation with 100% compatible operation keystroke for screentap and computational and operational reliability every bit as good as the original.

But wait, there's more! (sorry about that). Calculator12 is not stuck in the 80s. You have the option to work with cash flows in the cash flow diagram format, changing values or inserting/deleting cash flows with just a tap. Three independent cash flow scenarios can be evaluated side-by-side, and with capital multiplication you can evaluate an exit strategy for outside investors. Results can be emailed from Calculator12 so you don't have to redo things like an amortization schedule or comparative investment report at your lap or desktop. 

And you can see what was once hidden... the contents of the financial registers or optionally the stack are always displayed. For me at least confirming the accuracy of my entries relieves a lot of anxiety and prevents confusion when the results don't stack up. It's not programmable, but advance payment leasing functions have been pre-programmed in as well as conversions to APR and Effective Rate to fill some of the gaps. And it is blisteringly fast--what used to take 30 seconds now is done almost before your finger leaves the touchscreen. 

Calculator12 was the very first emulator of that physical machine on the App Store, v1.0 released July 30th of 2008, introducing features (now almost universally copied) that take advantage of the unique features of iOS to improve your ability to deal with financial problem solving. There are lots of emulators now, but only one that has moved out of the 80s. (this one!)

*** This application listing provides an upgrade path for early adopters to the redesigned and renamed Calc-12E. It is identical to Calc-12E and is maintained on the App Store to provide a way for existing customers to upgrade their original purchase to Calc-12E free-of-charge... It will appear on your home screen as Calc12E***

## Key features

- RPN financial calculator emulation
- Cash flow diagram format
- Three independent cash flow scenarios
- Capital multiplication for investors
- Emailable results
- Display of financial registers/stack
- Pre-programmed leasing functions

## Recent user reviews (10 of 31)

All indexed reviews: https://appshunter.io/ios/app/calculator12-rpn/id286506398/reviews.md

### 3/5 — Numbers too small

*2018-01-09, version 4.2.2*

Please make the numbers larger.  They are too small to be accurately touched.

### 5/5 — Works fine

*2017-10-16, version 4.2.2*

I have used this for years with no problems. When HP is selling (finally!) their own version, which is buggy and costs more, I can't understand why someone thinks this is a rip- off.

UPDATE OCTOBER 2017: Nuts! When OS 11 came out, this app stopped working. I went to the developer’s website, and it appeared moribund. No activity, no indication at all that this was not just another orphan product. So, sadly, I laid down my $25. (!!) and got the HP version, which is fine, but stupid expensive. 

Now, out of nowhere, an update has appeared which seems to work fine with OS 11. Oh well.

Buy this version, it saves you money and works well, at least as far as I can tell after a short time.

### 4/5 — Love the app — Please fix Landscape

*2017-10-05, version 4.2.1*

Great app, use it all the time.  When are you going to fix the landscape mode.  It appears to be wrong since the IOS11 update

### 5/5 — Nice job!

*2013-11-29, version 3.5.0*

This is a very nice implemtation of our beloved 12c.  I love all the extra functionality.  It's a little hard for me to use though, because some of the keys aren't where I'm used to seeing them.  On the iPad, I hate that the stock background flashes before switching to my chosen background.  Is there any way to get rid of that?  Great calculator though and I haven't noticed any other issues with it.

### 5/5 — The best!

*2013-11-10, version 3.5.0*

This is the best iPhone implementation of our favourite HP 12C calculator! Not only does it have all the features of the 12C, it also smartened it up with what a modern smartphone can offer with extra display info and conveniences. The pricing is also just right. Although I also have HP’s 15C port on my iPhone and use that for the various mundane calculations in a simplified portrait format, this one from Stone Meadow Development is my go-to for anything above that. No regret for the purchase from quite a while back and the support has been fantastic, now iOS7 updated. Can’t recommend enough!

### 5/5 — Better than the real thing

*2012-10-02, version 3.4.0*

Everything great.  The only complaint I have is the enter button is below and right next to this new "undo" button. The new button is a great idea.  but for someone who has used the 12c for years it is very easy to hit undo instead of enter if you are a little quick.

### 4/5 — Hp12c

*2012-03-11, version 3.4.0*

This calculator is a horrible rip off

### 4/5 — Click

*2012-01-28, version 3.4.0*

Get rid of the annoying key click!

### 3/5 — Nice Calculator, but no iPod Music!

*2009-09-05, version 0*

Sure, it's a nice calculator that does improves on the HP 12c, but it turns off the music when you use it. It's just a calculator, for cryin' out loud.

### 5/5 — A substantial improvement over the HP 12c

*2009-07-18, version 0*

The HP 12c is a standard - these folks kept the standard and improved it dramatically. HP simply recreated their calculator on an iPhone - didn't give any thought to improving it.

In my mind, my "flagship" differentiator is the cash flow viewer/editor... if you've never tried it it's slick IMHO. It allows you to see your cash flow entries as a cash flow diagram, and edit them (including adding and deleting individual cash flows) using the visual format--with the HP you can only delete the last cash flow and to do so you have to change the value of the n-register and you can't add a cash flow in the middle of your series. If you messed up entering the cash flows, you have to start over from CFo.

Emailing results, in particular amortization tables and calculations dealing with cash flows and one-tap access to the forum's FAQ page is very helpful - these guys did it right!!

## Frequently asked questions about Calculator12 RPN

### What does Calculator12 RPN do?

Calculator12 RPN offers a faithful emulation of a popular financial calculator, providing accurate calculations and operational reliability. It includes modern features like cash flow diagrams, scenario comparison, and the ability to email results, enhancing the functionality of the classic device.

### What are the key features of Calculator12 RPN?

Key features include a rock-solid emulation of a classic financial calculator, cash flow diagram format, the ability to evaluate three independent cash flow scenarios side-by-side, capital multiplication for investor exit strategies, and emailable results. It also displays financial registers or the stack and includes pre-programmed leasing functions.

### Is Calculator12 RPN free to use?

Yes, this application listing provides an upgrade path for early adopters to a redesigned version and is maintained on the App Store to allow existing customers to upgrade their original purchase free of charge. It appears on the home screen as Calc12E.

### What devices is Calculator12 RPN compatible with?

The app is designed for iPhone, iPod touch, and iPad devices. It leverages the unique features of iOS to improve financial problem-solving capabilities.

### Who would benefit from using Calculator12 RPN?

This app is ideal for students, financial professionals, investors, and anyone who needs a dependable and enhanced financial calculator. Its emulation of a classic device appeals to those familiar with it, while its modern features offer significant advantages for current financial analysis.

## Version history (last 1 release)

### 4.2.3 — 2019-02-12

This app has been updated by Apple to display the Apple Watch app icon.

Bug fix: The keyboard isn't squished anymore when launching in landscape on an iPad

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## More apps by Stone Meadow Development LLC

- [Calc-12E RPN Financial](https://appshunter.io/ios/app/calc-12e-rpn-financial/id294438793)
- [Resuscitate! CPR AED & Choking](https://appshunter.io/ios/app/resuscitate-cpr-aed-and-choking/id363393502)

All apps by Stone Meadow Development LLC: https://appshunter.io/developer/286506401

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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 2026-06-10.*