In MedCalc, as in other spreadsheets, a cell can contain a text or string entry, or it can contain a number or a formula.

An example or a string entry is a name such as e.g. Howard. When used in a formula, strings must be placed between quotation marks, e.g. "Howard".

A cell can also contain a number, negative or positive, and with or without a decimal fraction. E.g. 5, -23.5, 0.03. The number of decimals displayed globally in the spreadsheet is selected in the Format spreadsheet box. However, a different number of decimals may be selected for a particular variable on the Column tab of this dialog box.

A formula may be a simple mathematical formula, such as e.g. SQRT(36). This formula will return the value 6, which is the square root of the number 36. Alternatively, the number 36 may be entered in a different cell of the spreadsheet, and the SQRT function can take the address of this cell as an argument, e.g. SQRT(B5).

Most of the formulas available in MedCalc work similar to their equivalents in other spreadsheet programs. When a formula begins with a cell address, this must be preceded by a = or + sign, but MedCalc formulas must not be preceded by the = character.