Folder Size is a powerful utility that displays a count of the total number of files and subfolders in a particular folder, and the cumulative size of those files. It does a lot more than that, though...

Right-click any folder or file icon, or in a blank space in the window, and choose Folder Size from the ShellToys XP menu, and the Folder Size window will analyze the folder's contents and displays the results as a tree view. (If you right-clicked a file, you'll see details of the folder containing that file. If you right-clicked the window background, you'll see details of the current folder's contents.)

Information is listed under 4 columns:

Folder: Displays the name of each folder, just as Windows Explorer does.

%: Displays the percentage size of each folder in relation to its parent folder. The percentage values of a folder's contents should add up to roughly 100. A small indicator-image beside the figure shows the largest folders at a glance.

Size: Displays the total size of each folder's contents, including all its files and subfolders. Different text colors are used to draw your attention to MB and GB (megabyte and gigabyte) values.

Wasted: Displays the total amount of wasted space (see below) in each folder, including its subfolders. If the wasted space is greater than the size of the files, this value is highlighted in green to indicate that the folder contains many files that are smaller than the cluster size; if you don't use these files regularly, you could consider placing them in a zip archive to save space.

Allocated: Displays the total amount of disk space used by a folder's contents (Size+Wasted).

Click any folder to see additional information in the panel below. This information tells you the total number of files and subfolders in the selected folder, and the name and size of the largest file it contains. You'll also see information relating to the disk itself - its capacity, free space, file system type, and cluster size (see below).

You can also select multiple items in the list (by holding Ctrl or Shift when clicking items) to see their cumulative size displayed in the panel below.

Toolbar and Context Menu
From the left, the toolbar buttons do the following:

Expand All: Expands all nested items in the tree.

Collapse All: Collapses all expanded items. You can use the spacebar to toggle between expand-all and collapse-all.

Choose Folder: Displays a standard folder dialog, letting you pick a different folder to analyze. Keyboard fans can use Ctrl+F.

Stop: If a large folder or drive is being scanned, click Stop (or press Esc) to cancel the scan. The results so far will be shown, although they will only be accurate for folders whose contents have been fully scanned.

Cluster size and Rescan button: Allows you to analyze a folder using a different cluster size (see below).

To close this window, press Ctrl+Q.

Open Folder: opens the selected folder, letting you see the files it contains.

Scan Folder: causes Folder Size to scan this folder only, giving you a clearer view of its contents.

By default, Folder Size uses the actual cluster size of the current disk to calculate wasted space. The cluster size is shown in the information panel at the bottom of the window. However, it can be useful to analyze a folder using a different cluster size, and the drop-down list in the toolbar lets you do this. For example, you may want to find out whether a folder's contents will fit onto a CD-ROM (which has a cluster size of 2 KB). The Allocated column tells you the total amount of space required for the selected folder. If it's less than the capacity of your CD-ROM, the files will fit.

(Tip: You can scan an empty, formatted, disk to see its cluster size and capacity displayed in the information panel at the bottom of the window.)

• To rescan the current folder using a different cluster size for analysis, pick a new size from the drop-down list and click the Rescan button (or press Enter).

• To scan a different folder using a different cluster size, pick a new size from the list, then click the Choose Folder button (Ctrl+F) to select the folder.

Note: Whenever you choose a folder on a different drive, the cluster size is always set to the correct value for that drive.