Produce Subtotals for your data

Here are the steps to follow in this lesson:

Sort your data according to the field (column) by which you wish to group your records.
From the DATA menu select SUBTOTALS.
In the Subtotals dialog box confirm the correct field and select the FUNCTION you wish to use. There are 11 possible functions (including SUM, AVERAGE, MIN, MAX)
Check to FIELDS that you want to be subtotaled and then click OK.
Excel automatically OUTLINES your data. Click the Expand and Collapse buttons on the outline to see more or less detail. Click the Outline Levels to see different views of your subtotals.
Explore the other options in the Subtotal dialog box (First choose Data – Subtotals.)
You can remove ALL Subtotals in the Subtotal dialog box.