Creating a formula in Excel 2013 is as easy selecting the cell where you want to display results and entering the formula in the Formula Bar or clicking the "Insert Function" button, choosing the right function for your desired results and selecting the cells containing the data. Excel's range finder makes it simple for you to view or change the cells you are using to create either a simple formula or any formula that uses a function.
Click on the cell in which you want the results displayed. Type "=" into the formula bar and type the formula you wish to use. Alternatively, click the "Insert Function" button, search for and select the correct function and click "OK." Select or enter the cells you wish to use in the formula.
Double-click the cell containing the formula. The range finder color codes the cells containing the data to match the formula reference.
Change the cell or range referenced by dragging the range finder border to the desired cell or range.
Add or remove cells in the reference using the drag handle in the lower-right corner of the range finder border. Move the border to include only those cells to which you want to refer.
Press "Enter" to update changes made using the range finder. Press "Ctrl-Shift-Enter" if you are updating an array formula.
If you double-click a cell containing a formula and the color-coded border does not have a square corner, this means the formula refers to a named range of cells.