Type the formula in the first cell of the column
Press Enter
Select the cell with the formula
Double-click the fill handle to copy the formula down the column
Drag the fill handle down to the last row if needed
Select the entire range and press Ctrl+D to fill down
Convert the range to an Excel Table and enter the formula once in the first row
Use a structured reference formula in the table to auto-fill the entire column
Select the entire column and enter the formula, then press Ctrl+Enter
Copy the formula cell and paste it into the full column range
Use AutoFill options if Excel does not fill the column automatically