What symbol always starts a formula in a spreadsheet?

In a spreadsheet, formulas are initiated with the equals sign. This symbol signals to the software that what follows is a formula that should be calculated rather than plain text or a value. The equals sign is universally accepted in spreadsheet programs, such as Microsoft Excel and Google Sheets, as it indicates that the user intends to perform calculations, reference cells, or apply functions.

For example, when you type "=A1+B1", the spreadsheet interprets this as a command to add the values contained in cells A1 and B1. The presence of the equals sign is essential; without it, the spreadsheet would not recognize the input as a formula, and it would simply treat it as a string of text. This foundational aspect of formula writing is key to leveraging the full capabilities of spreadsheet software for data analysis, calculations, and reporting.