---
title: "Free42 - Reviews, Revenue and Downloads in United States | Apple App Store"
description: "Free42 is a re-implementation of the HP-42S calculator and the HP-82240 printer. It is a complete rewrite, not using any HP code, and it does not require an HP-42S ROM image. Free42 is an Open Source "
---

# Free42 — United States
> HP-42S Calculator Simulator

![Free42 App Icon](https://is1-ssl.mzstatic.com/image/thumb/Purple211/v4/a1/43/a1/a143a1bc-ab3b-ea19-9862-05d0c475e74e/AppIcon-0-0-1x_U007epad-0-1-85-220.png/400x400bb.png)

**Developer:** [Thomas Okken](https://apptail.io/developer/thomas-okken-jlm)
**Category:** Utilities
**Rating:** 4.8/5 (282 ratings)
**Price:** Free
**Bundle ID:** com.yourcompany.Free42
**Store:** Apple App Store
**Country:** United States
**Version:** 3.3.12 (released 2026-05-05)
**Original Release:** 2009-11-05

**App Store Link:** [Download on Apple App Store](https://apps.apple.com/us/app/app/id337692629)
**AppTail Page:** [https://apptail.io/app/free42-Oxve/united-states](https://apptail.io/app/free42-Oxve/united-states)

## Free42 Description
Free42 is a re-implementation of the HP-42S calculator and the HP-82240 printer.
It is a complete rewrite, not using any HP code, and it does not require an HP-42S ROM image.
Free42 is an Open Source project. The executables and source code are released under the terms of the GNU General Public License, version 2.
All third-party code used in Free42 is either in the public domain, or licensed under terms compatible with GPLv2, or used with the authors' permission.

## Free42 Screenshots
- [Screenshot 1](https://is1-ssl.mzstatic.com/image/thumb/Purple126/v4/84/12/e7/8412e7c5-7eba-d09d-a984-a7df44d0c51b/mzl.ntjnekpu.png/640x960.png)
- [Screenshot 2](https://is1-ssl.mzstatic.com/image/thumb/Purple116/v4/b6/73/3e/b6733e37-2365-9ac8-a608-9c4a295f0300/pr_source.png/640x960.png)
- [Screenshot 3](https://is1-ssl.mzstatic.com/image/thumb/Purple116/v4/02/ce/c3/02cec3b1-4635-76a2-52c7-bf753a013bcd/pr_source.png/960x640.png)

## Free42 Rating Breakdown in United States
- 5 stars: 253 (90%)
- 4 stars: 11 (4%)
- 3 stars: 7 (2%)
- 2 stars: 3 (1%)
- 1 stars: 8 (3%)

## Free42 Reviews in United States

### ***** "Fantastic!"
So nice to have this available.  I have always been a diehard HP RPN calculator fan.  This app is a faithful and convenient reproduction.
-- tom_ortiz, 2024-08-29

### ***-- "Square root function not working"
Not sure why, but the square root function doesn’t seem to be working properly now.  Was working okay before. Not sure if other functions are also impacted.  Used to love this up until this happened
-- Superachar, 2024-06-26

### ***** "Fantastic App!"
I have always used HP RPN calculators spanning a period of over fifty years and this App is a faultless rendition of the original calculator.

One really niggling problem is that the screen has rotated 90 degrees to landscape. Trying to get it back to portrate does not work. Any ideas? Any fix coming?

Ray Shead
-- RPN Friend, 2024-02-09

### ***** "Thank you, thank you!!!"
I’ve been using my hp42 since buying it the day it was in stock for sale. Its a one-owner! On back it says 1987 Made in USA. SERIAL No …A11141. I digress. Some of my keys have started to act up after 36 years of perfect service. Finding Free42 is a godsend! I’m running it on an iPhone SE. I re-entered some really old programs I’ve kept on my 42s and they work flawlessly. I am so grateful you’ve created this app. Thank you, thank you!
-- riccko, 2024-02-08

### ***** "Love this calculator"
I’ve been a fan of RPN for over 40 years. This calculator works great. I don’t typically use it for much more than simple calculations but I use it daily. I absolutely love the haptic feedback with key presses. It’s gives great indication when you’ve typed a number.
-- TonyGixxer, 2023-12-28

### ***** "Great app"
Terrific!
-- nate12345, 2023-12-04

### *---- "Calculator"
I’ve had a HPC 12 for years, and it was very simplistic to work with.
This calculator is very complex and not easy to use.
Does it even come with an instruction manual?
-- Trecio, 2023-07-18

### ***** "Great RPN Calculator"
I first started with my first RPN calculator when I worked in electrical engineering in the eighties with my HP15C. I used it very extensively, writing time saving programs for my job. (Also, the approximately $90 or so purchase price at the time, with a young family really hurt!) Although, my present position for the last twenty years doesn’t require anything advanced, RPN is still my first choice for a calculator. The “Free42” RPN calculator is easy to use & works well. I’m sorry to say that I haven’t used very many of the advanced functions. I have also loaded the windows version on my computer at work, with a skin that is similar to the HP15C (for sentimental reasons…). Also browsing the developer’s website, I was surprised to see that this software was created in 2004, has had many updates & is available for android, iPhone, Windows, Linux & Mac. Looking thru the updates listed on his website, this developer is very committed to this product. (it’s sad, my real HP15C calculator is just gathering dust in my dresser top junk drawer, half the time, the batteries die due to drainage from lack of use, it’s just too easy to reach for my iPhone that’s already in my pocket) My only complaint is the name. Free42 makes this product sound cheap & junky, it is not! Please consider a better name.
-- Rick, Honda Owner, 2023-04-06

### ***** "I feel so guilty."
I’ve been using Free 42 for years, I’ve never paid a penny! I paid for other HP emulators that I only sparingly used before deleting. 
At least add a menu item in ‘about’ that we can buy you a coffee!😊
-- @realDonaldPunk, 2022-10-15

### ***** "Awesome app!"
I was elated to find this FREE app. I used a HP41C in college many moons ago and absolutely love RPN. Later on I used the HP42 at my job. Kudos to the developer for creating this fabulous app!
-- Tikka Owner, 2022-10-03

[View all Free42 reviews and detailed analytics on AppTail](https://app.apptail.io/signup?utm_campaign=ai-crawl&utm_content=reviews)



## Free42 Discovered Keywords
- rpn calc
- rpn
- rpn calculator free
- rpn scientific calculator
- 42s rpn calculator
- free42


## Free42 Available In
- [United States](https://apptail.io/app/free42-Oxve/united-states)
- [Germany](https://apptail.io/app/free42-Oxve/germany)
- [Canada](https://apptail.io/app/free42-Oxve/canada)
- [Switzerland](https://apptail.io/app/free42-Oxve/switzerland)
- [France](https://apptail.io/app/free42-Oxve/france)
- [Australia](https://apptail.io/app/free42-Oxve/australia)
- [Japan](https://apptail.io/app/free42-Oxve/japan)
- [United Kingdom](https://apptail.io/app/free42-Oxve/united-kingdom)
- [Italy](https://apptail.io/app/free42-Oxve/italy)
- [Brazil](https://apptail.io/app/free42-Oxve/brazil)
- [Sweden](https://apptail.io/app/free42-Oxve/sweden)
- [Netherlands](https://apptail.io/app/free42-Oxve/netherlands)
- [Denmark](https://apptail.io/app/free42-Oxve/denmark)
- [Spain](https://apptail.io/app/free42-Oxve/spain)
- [Austria](https://apptail.io/app/free42-Oxve/austria)
- [Belgium](https://apptail.io/app/free42-Oxve/belgium)
- [Mexico](https://apptail.io/app/free42-Oxve/mexico)
- [Norway](https://apptail.io/app/free42-Oxve/norway)
- [Hong Kong SAR China](https://apptail.io/app/free42-Oxve/hong-kong)
- [Russia](https://apptail.io/app/free42-Oxve/russia)
- [South Africa](https://apptail.io/app/free42-Oxve/south-africa)
- [China](https://apptail.io/app/free42-Oxve/china)
- [New Zealand](https://apptail.io/app/free42-Oxve/new-zealand)
- [Ireland](https://apptail.io/app/free42-Oxve/ireland)
- [Poland](https://apptail.io/app/free42-Oxve/poland)
- [Czechia](https://apptail.io/app/free42-Oxve/czechia)
- [Greece](https://apptail.io/app/free42-Oxve/greece)
- [Croatia](https://apptail.io/app/free42-Oxve/croatia)
- [Argentina](https://apptail.io/app/free42-Oxve/argentina)
- [Taiwan](https://apptail.io/app/free42-Oxve/taiwan)
- [South Korea](https://apptail.io/app/free42-Oxve/south-korea)
- [Philippines](https://apptail.io/app/free42-Oxve/philippines)
- [Chile](https://apptail.io/app/free42-Oxve/chile)
- [India](https://apptail.io/app/free42-Oxve/india)
- [Slovenia](https://apptail.io/app/free42-Oxve/slovenia)
- [Thailand](https://apptail.io/app/free42-Oxve/thailand)
- [Türkiye](https://apptail.io/app/free42-Oxve/turkey)
- [Vietnam](https://apptail.io/app/free42-Oxve/vietnam)
- [Finland](https://apptail.io/app/free42-Oxve/finland)
- [Ecuador](https://apptail.io/app/free42-Oxve/ecuador)
- [Colombia](https://apptail.io/app/free42-Oxve/colombia)
- [Portugal](https://apptail.io/app/free42-Oxve/portugal)
- [Hungary](https://apptail.io/app/free42-Oxve/hungary)
- [Egypt](https://apptail.io/app/free42-Oxve/egypt)
- [Malaysia](https://apptail.io/app/free42-Oxve/malaysia)
- [Latvia](https://apptail.io/app/free42-Oxve/latvia)
- [Indonesia](https://apptail.io/app/free42-Oxve/indonesia)
- [Singapore](https://apptail.io/app/free42-Oxve/singapore)
- [Ukraine](https://apptail.io/app/free42-Oxve/ukraine)
- [Slovakia](https://apptail.io/app/free42-Oxve/slovakia)
- [Peru](https://apptail.io/app/free42-Oxve/peru)
- [Qatar](https://apptail.io/app/free42-Oxve/qatar)
- [Romania](https://apptail.io/app/free42-Oxve/romania)
- [Belarus](https://apptail.io/app/free42-Oxve/belarus)
- [Saudi Arabia](https://apptail.io/app/free42-Oxve/saudi-arabia)
- [Azerbaijan](https://apptail.io/app/free42-Oxve/azerbaijan)
- [United Arab Emirates](https://apptail.io/app/free42-Oxve/united-arab-emirates)
- [Kuwait](https://apptail.io/app/free42-Oxve/kuwait)
- [Kazakhstan](https://apptail.io/app/free42-Oxve/kazakhstan)
- [Lebanon](https://apptail.io/app/free42-Oxve/lebanon)
- [Sri Lanka](https://apptail.io/app/free42-Oxve/sri-lanka)
- [Malta](https://apptail.io/app/free42-Oxve/malta)
- [Estonia](https://apptail.io/app/free42-Oxve/estonia)
- [Nigeria](https://apptail.io/app/free42-Oxve/nigeria)
- [Algeria](https://apptail.io/app/free42-Oxve/algeria)
- [Nepal](https://apptail.io/app/free42-Oxve/nepal)
- [Dominican Republic](https://apptail.io/app/free42-Oxve/dominican-republic)
- [Panama](https://apptail.io/app/free42-Oxve/panama)
- [Pakistan](https://apptail.io/app/free42-Oxve/pakistan)
- [Israel](https://apptail.io/app/free42-Oxve/israel)
- [Botswana](https://apptail.io/app/free42-Oxve/botswana)
- [Cayman Islands](https://apptail.io/app/free42-Oxve/cayman-islands)
- [Guyana](https://apptail.io/app/free42-Oxve/guyana)
- [Barbados](https://apptail.io/app/free42-Oxve/barbados)
- [Angola](https://apptail.io/app/free42-Oxve/angola)

---

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