GNOME Calculator
GNOME Calculator icon 2021.svg
GNOME Calculator 40 (released in 2021-03).png
GNOME Calculator 40
Stable release
41.0[1] Edit this on Wikidata / 18 September 2021; 10 months ago (18 September 2021)
Preview release42.alpha[2] (18 January 2022; 6 months ago (2022-01-18)) [±]
Written inC, Vala
Operating systemUnix-like
TypeSoftware calculator
LicenseGPL-3.0-or-later Edit this on Wikidata

GNOME Calculator, formerly known as gcalctool, is the software calculator integrated with the GNOME desktop environment. It is programmed in C and Vala and part of the GNOME Core Applications.



The GNOME calculator uses the common infix notation for binary functions, such as the four basic arithmetic operations. Unlike many other calculators, it uses prefix notation, not postfix notation for unary functions. So to calculate e.g. the sine of one, the user must push the keys "sin", "1", "=" - not "1", "sin" as on many other calculators.

The decimal separator on the number pad is based on the general keyboard layout since version 3.12.3.[3]

Variable handling

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Advanced, Financial, and Programming modes present features for storing and retrieving values labeled as variables. R is the symbol for variable, used on GUI buttons ←R (insert variable) and →R (assign variable).

Variable names are case-sensitive alphabetical string without spaces. Variable values are numerical strings.

Values are assigned to variable names by entering in the GUI text input/result field a variable name followed by 0 or more spaces, followed by the = character, followed by 0 or more spaces, followed by either a numeric value or an existing variable name, e.g. "x = 2" or "result = subtotal" (if subtotal was already assigned a numeric value). A numeric value is assigned to the first variable name. If the value was entered as an existing variable name rather than as a numeric value, the existing variable's value is assigned to the first variable name. Assignment to a variable name that does not exist creates the new variable by name with the assigned value. The →R (assign variable) GUI button shows a popup menu of existing variables (and the current value of each), to which selected variable is assigned the current numeric value displayed in the calculator, just as if that variable name were entered in the GUI text field followed by a = followed by the numeric value.[citation needed]

Entering a variable name into the GUI text field substitutes the variable value for the variable name when the expression in the GUI text field is evaluated (e.g. when the keyboard <Enter> button or the = GUI button is pressed). The ←R (insert variable) GUI button shows a popup menu of existing variables (and the current value of each); the selected variable name is inserted (appended) into the GUI text field.[citation needed]

Two predefined variables are available from the ←R (insert variable) GUI button: ans and rand. ans contains the last "answer" value calculated by the calculator as a result. rand contains a random value between 0.0 and 1.0 (the value is not displayed; a rand variable is evaluated in an expression when calculating a result).

Variable names and values persist between launch and quit of the application.

See also


  1. ^ "gnome-calculator 41.0".
  2. ^ Petridis, Jordan (18 January 2022). "GNOME 42.alpha released". GNOME Mail Services (Mailing list). Retrieved 22 March 2022.
  3. ^ "gnome-calculator 3.12.3". 2013-06-15.