Almost every month, I suggest the Subtotal feature to a reader. It's an easy-to-use feature that summarizes data by groups. You define the group and the summarizing function; Excel does the rest ...

Click the Data tab. Click Subtotal in the Outline group. In Excel 2003, Subtotals is on the Data menu. In the resulting dialog, choose Count from the Function dropdown.

On the Data menu choose "PivotTable and PivotChart report". Accept defaults ("Microsoft Office Excel list or database" and "PivotTable") and click Next.

You sorted the data earlier by Category, so you don’t need to sort again. Click anywhere inside the data and click Subtotal (in the Outline group). In Excel 2003, choose Subtotals from the Data ...