Recalculates all changed formulas. If AutoCalculate is enabled, the Recalculate command applies only to formulas like RAND or NOW.
Choose Data - Calculate - Recalculate
Press F9 to recalculate. Press Shift+Ctrl+F9 to recalculate all formulas in the document.
After the document has been recalculated, the display is refreshed. All charts are also refreshed.
The Add-In functions like RANDBETWEEN currently cannot respond to the Recalculate command or F9. Press Shift+Ctrl+F9 to recalculate all formulas, including the Add-In functions.
References to Other Sheets and Referencing URLs or other external data
See source: http://help.libreoffice.org/Calc/References_to_Other_Sheets_and_Referencing_URLs*