HP16C
Utilities
Free · Designed for iPad. Not verified for macOS.
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
Ratings & Reviews
Fixed a crash when you overflowed the largest signed value at a 64-bit word size, for example, adding 1 to 2^63
The bad value got saved too, so the app would crash again on every launch until it was reinstalled. It now rolls over to the most negative number.
Thanks to the user who reported it.
The developer, Michael Doornbos, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Michael Doornbos
- Size
- 824.3 KB
- Category
- Utilities
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © OffGlobe, LLC 2026