PiCalculator! vs HP16C
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
PiCalculator!
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Do you love Pi, the most famous irrational number in mathematics? Do you want to challenge your smartphone and see how many digits of Pi it can compute? Do you want to learn more about the history and applications of Pi? If you answered yes to any of these questions, then PiCalculator is the app for you! PiCalculator is a fun and educational app that lets you calculate Pi with your smartphone. You can choose how many digits of Pi you want to compute, and watch as your smartphone works hard to find them. You can also see the progress and speed of the calculation, and compare it with other devices. You can also share your results and achievements with your friends on social media.
HP16C
This app faithfully recreates the legendary HP 16C Computer Scientist calculator, offering advanced hex arithmetic, bit manipulation, and base conversion. It features RPN, keystroke programming, and modern enhancements like a two-line display and haptic feedback.
- Full RPN calculator
- Integer arithmetic (HEX, DEC, OCT, BIN)
- Configurable word size (1-64 bits)
- Complete bit operations
- Keystroke programming
- Two-line display
- Haptic feedback
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A faithful recreation of the legendary HP 16C Computer Scientist calculator for iPhone, with a few modern upgrades. If you've ever needed to perform hex arithmetic, bit manipulation, or base conversion on your phone and been frustrated by the available options, this is for you. RPN-16C gives you the full power of the original HP 16C in your pocket. WHAT IT DOES - Full RPN (Reverse Polish Notation) calculator - Integer arithmetic in HEX, DEC, OCT, and BIN - Configurable word size from 1 to 64 bits - Unsigned, one's complement, and two's complement modes - Complete bit operations: shift, rotate, rotate through carry, AND, OR, XOR, NOT, mask, bit set/clear/test, count bits, left justify - Float mode with configurable precision (FLOAT 0-9) - Keystroke programming with labels, subroutines, loops, and conditionals - Storage registers with direct and indirect addressing - Programs can be imported from text (long-press the display to paste) ENHANCEMENTS OVER THE ORIGINAL - Two-line display: see both X and Y registers at once. No more guessing what's on the stack. - Wider LCD: displays all 32 bits in binary without scrolling. The original could only show 8 at a time. - Haptic feedback on every key press - State persistence: pick up right where you left off - SHOW function to peek at values in other bases FAIR WARNING This is a quirky calculator. It uses Reverse Polish Notation, has no equals key, and expects you to know what two's complement means. If you're looking for a simple calculator, this is not it. If you've ever wished you could do a bitwise rotate through carry on your phone, welcome home. DESIGNED FOR PROGRAMMERS The key layout matches the physical HP 16C exactly, including the f (gold) and g (blue) shift labels. If you know the original, you already know this one. The original HP 16C Owner's Handbook is freely available on the Internet Archive: https://archive.org/details/hp-16c_handbook
Screenshots
Verdict
The clearest difference is device support: HP16C at 2 against PiCalculator!'s —. HP16C also leads on iOS requirement (17.0 vs 26.0). On price and in-app purchases 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.
| Parameter | PiCalculator! | HP16C |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.3 (3 ratings) — better |
| Number of ratings | — | 3 — better |
| Update frequency | — | Weekly |
| Ads | — | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | — | iPhone, iPad — better |
| Requires iOS | 26.0 | 17.0 — better |
| Further details — not scored | ||
| Size | 1 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Nicolo Campari | Michael Doornbos |
In-app purchases
PiCalculator!
No in-app purchases
HP16C
No in-app purchases









