MathU RPN is an advanced scientific and fiancial calculator designed in the spirit of classic HP calculators. MathU RPN is based on the Reverse Polish Notation (RPN) entry system and combines more than 96 functions to create a calculator that meets the needs of professionals who use a calculator every day.

MathU RPN was created by a Ph.D from M.I.T. who is a MATLAB toolbox author and has 20 years of experience creating calculators for mobile devices. Dr. Clay M. Thompson of Creative Creek has harnessed the computational power of the iPhone to produce an accurate and high performance calculator.

General Features
- IEEE double precision accuracy (16 digits)
- High performance fast computations
- 20 storage registers
- 5 financial registers
- 16 high stack (switchable to 4)
- Supports international number separators
- Switch between portrait and landscape keypads
- Quick access to the preference and on-line manual
- Stack and Register view (accessible via [RCL][RCL]

Scientific Features
- Full set of trigonometric functions
- Full set of logarithmic and power functions
- Statistics functions
- Polar and rectangular conversions
- Repeated computations

Mortgage and Loan Features
- Time value of Money functions
- Compute mortgage and loan terms
- Solve for payments and interest rates
- Solve for IRR and NPV
- Date functions

Computer Science Features
- Number bases (HEX, OCT, DEC, BIN)
- Bitwise logical operations
- Masking and shifting functions
- Support for a wordsizes up to 48 bits
- Modular arithmetic

MathU RPN 3.0 has been reformatted to work on the iPhone and iPad. On the iPad MathU RPN maintains its orientation as the iPad is turned.

MathU RPN 3.0 a great programmer's calculator. The A-F keys are available right up front for easy entry in HEX mode and there are many functions for working with integers.

MathU RPN 3.0 is also a better financial calculator. There are new functions for computing mortgage amortization and cash flow computations like IRR and NPV, as well as functions for working with dates. Many of the existing financial functions have been extended to handle odd periods (conforming to the same conventions as the HP-12C). In addition, on tall devices (like the iPhone 5 or higher), the financial registers are displayed on the keypad.

The scientific side of MathU RPN has also been improved by adding functions for linear regression as well as computing the percent of total.

MathU 3.0.3 supports iOS 8.0 or higher.

For more info (including the users manual)
go to or use the built-in quick reference.

What's New

Version 3.0.4

Compatibility release for iOS 11.x. Fixes a few issues in the 3.0.3 release.

Ratings and Reviews

4.6 out of 5

7 Ratings

7 Ratings

Really great RPN calculator


I have been using this calculator for years and found it flawless for a RPN calculator. Reverse Polish Notation (RPN) calculators take less keystrokes than an algebraic version to complete a series of calculations.

This calculator faithfully executes the HP look and feel for those wanting combined scientific and business functions in one app. I cannot praise this calculator enough.

Again I appreciate the update... but maybe a little sooner next time?


I’m excited to see my favorite calculator finally get an update, but I do wish it was sooner... again. My big request is that you consider using the whole landscape for the iPhone X. Please, consider that and allowing me to display only 1 row of my stack. I thought I recalled that being an option many years ago.

Love this calculator!!!!


Best standard HP emulator I've ever used - now supports iOS 11! All the functionality you would expect from an HP scientific and financial calculator.

This is my primary calculator. Had MathU calculators since my PalmOS days. They have always been robust and reliable.


Creative Creek, LLC
9.8 MB
Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© 1998-2018 Creative Creek, LLC


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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