galculator is an open source scientific calculator supporting algebraic mode as well as Reverse Polish Notation (RPN).
Its features include arithmetic precedence handling, mathematical functions, different number bases (DEC, HEX, BIN, OCT) and angle bases (radiant, degree, and grad). For a complete list of features, please see below.
galculator’s formula entry mode aims to provide all the features of the algebraic mode (and even to go further).
galculator is written entirely in C and uses GTK 2 / GTK 3 to provide an attractive graphical interface.
There hasn’t been any significant development of the calculator since 2015.
Key Features
- Algebraic mode, RPN (Reverse Polish Notation) and Formula Entry mode. Formula entry mode accepts decimal numbers as input as well as hexadecimal, binary and octal numbers.
- Paper mode – a very simple graphical user interface along with the functionality of formula entry mode. “Do your calculations as you would do them on a paper”.
- Decimal, hexadecimal, octal and binary number base.
- Radiant, degree and grad support.
- Arithmetic precedence.
- Basic and Scientific Mode. Basic mode is intended for simple computations. Scientific Mode is galculator’s most powerful operation mode.
- User defined constants.
- User defined functions – called with the fun button next to the constant button and work like the other function buttons like sin, cos, etc.
- Trigonometric functions.
- Power, sqare root.
- Natural and common logarithm.
- Inverse and hyperbolic functions.
- Memory functions.
- Logical operations.
- Display RPN stack.
- Preferences dialog/configuration file.
- Display modules.
- Configurable variable type in HEX/BIN/OCT mode.
- Thousands separator.
- Quad-precision floating point.
- 112-bit binary arithmetic on systems with libquadmath.
- Copy and paste functionality.
- Keyboard shortcuts for arithmetic operations, popup menus, functions, display control, and menu shortcuts.
- Internationalization support – available in more than 20 translations including Spanish, Turkish, French, German, Lithuanian, Hungarian, Russian, Slovakian, and Polish.
Website: github.com/galculator/galculator
Support:
Developer: Simon Floery
License: GNU GPL v2 or any later version

galculator is written in C. Learn C with our recommended free books and free tutorials.
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Read our verdict in the software roundup.
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galculator is good but DEAD since 2015, no updates on their site
complement for HEX calcs does not work right in functions
~(x)+1 going from HEX to DEC always gives ZERO
Yes, the article notes the software is not currently maintained.