Excel is packed with lots of great tools. One of my favourites is the Subtotals. Here you can take a list, sort it into order so that appropriate items are grouped together, then click a button and it will determine the subtotal for each of those groups.
Not only will it create subtotals, it will do averages, max and min to find the highest and lowest values.
Check out the video tutorial below to see it in action. For more tutorials see my website www.jargonfreehelp.com.