How do I add formulas to Google Sheets using Google Apps Script?

Question

How do I add a formula like:

=SUM(A1:A17)

to a range of fields using the Google Apps Script API for Google Sheets?

Answer 1

This is done using the setFormula for a selected cell. Below is an example of how to do this.

var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheets()[0];

var cell = sheet.getRange("B5");
cell.setFormula("=SUM(B3:B4)");

You can also use setFormulaR1C1 to create R1C1 notation formulas. Example below.

var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheets()[0];

var cell = sheet.getRange("B5");
// This sets the formula to be the sum of the 3 rows above B5
cell.setFormulaR1C1("=SUM(R[-3]C[0]:R[-1]C[0])");

To add several formulas to several fields use setFormulas. Example below

var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheets()[0];

// This sets the formulas to be a row of sums, followed by a row of averages right below.
// The size of the two-dimensional array must match the size of the range.
var formulas = [
  ["=SUM(B2:B4)", "=SUM(C2:C4)", "=SUM(D2:D4)"],
  ["=AVERAGE(B2:B4)", "=AVERAGE(C2:C4)", "=AVERAGE(D2:D4)"]
];

var cell = sheet.getRange("B5:D6");
cell.setFormulas(formulas);