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Hypatia Command Line Calculator

The content of this section of the website is not related to its main purpose of providing carefully edited e-books. I have moved these pages here from my former and now defunct IT services website


Hypatia is a calculator, basically reproducing the functionality of a pocket calculator, that uses an extended version of Reverse Polish Notation (RPN).

It is a text-based program that you can either start from the command line prompt or from the Windows desktop, where it will create its own console window.

While it offers advanced features that make it a powerful tool, it can be easily used for basic calculation purposes.

To use Hypatia, you need some knowledge of RPN (Reverse Polish Notation) – see A short introduction you find in the file hy-rpn.txt that is included in the download package.

The name Hypatia is a tribute to the mathematician, astronomer and philosopher Hypatia of Alexandria. For details about her, see

Hypatia is freeware

No registration is needed – just download! (See below)

Current version: 0.30


Hypatia offers the usual functionality of a scientific pocket calculator, including algebraic, logarithmic and trigonometric functions. It has functions for measurement unit conversion, six different percentage functions, two random number functions, and a few statistical functions that go beyond the regular RPN syntax. It supports decimal, hexadecimal and binary number formats.

Hypatia supports an unlimited number of named variables that you can save to disc in plain text format and re-import later, and allows you to easily define your own constants. It can read data and calculations from plain text files, and can write input and results to a log file.

Hypatia can be used in dialogue mode, which offers the full functionality, or in "command line calculation mode" for quick single calculations.


Any Windows version from Windows 95 to 7 (or probably 8, though I haven't tested it). Hypatia has a very small footprint, virtually no requirements are made regarding disk space, memory or processor speed.


Basically, just download, unpack and run. Details see file hy-setup.txt that is included in the download package. The executable file is hy.exe.

To quit the program, use either the q, quit or exit command.

Hypatia does not touch the registry or in any other way modify the system.

Programming language

Hypatia is written in the Euphoria programming language, version 3.1. Euphoria is open source, and available at

One day I'll plan to port it to Euphoria 4, but this may take some time.


You can use the executable file freely. Regarding the source files, please note the following terms of license:

1. You may use the Hypatia source files to create executable files for different operating systems (Linux, Unix).

2. You may modify the source files according to your personal needs, and create executable files from these modified source files, as long as you do not remove the original copyright note that is displayed with the -? command line option and the ? command, and add a note stating that this is a version modified by you.

3. You must not use the modified or unmodified source files commercially without the author's consent.

Please report to me all bugs you may find, as well as possible errors or lack of clarity in the documentation.


For bug reports, information, support requests, feature suggestions or any other kind of feedback please mail to the author, Robert Schaechter, at, and include "Hypatia" in the subject line.

Note that the software and the documentation files are provided "as is," that the author assumes no responsibility for their correctness, and that all support by the author is given on a voluntary basis.


Version 0.30, from 08/22/2011

Windows console executable file, and documentation files:

Download the zip file, preferably into an empty directory created for this purpose, and unzip the compressed file using any convenient unpacking utility – you will get one executable file hy.exe and six documentation files in plain text format. Follow instructions given in the hy-setup.txt file. The main documentation file is hy-overview.txt.

Euphoria source files (you do not need this for using Hypatia):

By downloading the source code you agree to accept the terms of license (see above).

Known problems

FDEC rounds inconsistently:


? 2.35

= 2.3

? 2.55

= 2.6

This is a problem of the Euphoria interpreter, maybe it will be fixed when Hypatia gets ported to Euphoria 4.

Warning: Repeated copying to clipboard (COPY or COPYALL) can cause the program to give wrong results and to crash! Do not use COPYALL for more than a few lines, and use COPY with care!

Version history

0.30 – 08/22/2011

New unit conversion function:
miles per gallon <-> liters per 100km

0.29 – 12/21/2009

New unit conversion functions:
avoirdupois ounces, troy ounces <-> grams.

0.28.3 – 01/01/2009

Bug fix: due to the binary representation of decimal numbers in the Euphoria interpreter, the functions FLOOR, FRAC, INT and RD sometimes behaved unexpectedly – hopefully, this is fixed.

0.28 – 11/12/2008

New feature: function FRAC (fractional part of decimal number).

0.27 – 10/28/2008

New features: option to use comma as decimal separator; option to copy all results to the clipboard.

0.25.1 – 12/12/2007

Bug fix: CLC mode in combination with ini file.

0.25 – 12/04/2007

New feature: you can copy results to the Windows clipboard.

0.24 – 10/23/2007

First published version.


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