Free42 vs NerdCalc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Free42
This application is a faithful re-implementation of the HP-42S scientific calculator and its associated printer. It offers full functionality without requiring original HP ROM images and is an open-source project.
- HP-42S calculator simulation
- HP-82240 printer simulation
- Open source project
- No HP ROM required
- Complete rewrite
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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.
NerdCalc
Perform calculations across binary, hexadecimal, and decimal number bases simultaneously. Easily switch input modes and see results update instantly for all bases. Supports unsigned and 2's complement for negative numbers, along with arithmetic, logic, and bitwise operations.
- Simultaneous base display
- Switchable input modes
- Unsigned and 2's complement support
- Arithmetic operations
- Logic operations
- Bitwise shifting
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NerdCalc is a binary, hexadecimal and decimal calculator that displays all three number bases at the same time. With NerdCalc, you can quickly switch which base you are inputting and the result of your calculations is always updated for all three bases, no matter what the current input mode. NerdCalc supports both unsigned and 2’s complement, to allow for negative numbers, and can perform basic arithmetic and logic operations as well as bitwise shifting. Enjoy!
Screenshots
Verdict
The clearest difference is update cadence: Free42 at every 9 days against NerdCalc's every 19 months. Free42 also leads on review sentiment (94% vs 85%) and device support (3 vs 1). On price, rating, ratings volume and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 4.8 for Free42 against 4.8 for NerdCalc. Both are backed by a comparable volume of ratings — 284 and 183 respectively. Written reviews are what separate them: 94% of Free42's written reviews are positive against 85% of NerdCalc's.
Free42 ships an update every 9 days, NerdCalc every 19 months. The most recent releases landed on October 18, 2026 and October 19, 2026 respectively.
| Parameter | Free42 | NerdCalc |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (284 ratings) | 4.8 (183 ratings) |
| Positive reviews | 94.4% of reviews — better | 84.8% of reviews |
| Number of ratings | 284 — better | 183 |
| Update frequency | Every 9 days — better | Every 19 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 9 MB | 0 MB |
| Age rating | 4+ | 4+ |
| Developer | Thomas Okken | Nidal Fakhouri |
Customer experience
Free42
NerdCalc
Bugs and requests
Free42
Reported bugs
2 issues- Occasional issues with Solver function
- Store and Recall functions not working properly
Requested features
3 requests- Display all registers (X, Y, Z, T, Last X) simultaneously
- Ability to share/transfer programs between devices
- Improved use of screen real estate on larger displays
NerdCalc
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Free42
No in-app purchases
NerdCalc
No in-app purchases
