Folder Size

Folder Size is a freeware Windows utility that visually displays the size of the folders on the local drives, thus helping you see the largest folders on the disks.
The application has been designed as a file browser, so it's all very easy to use. You can browse the disk content just like you're using a typical file browser, with the right panel used for displaying folder information.
Folder Size shows small bar graphs to show the actual size of the existing folders and clicking on any of them displays the content.
There is no configuration screen, no other options and just a basic interface, so it's almost impossible to get lost in the interface.
Instead, the application works like a charm regardless of the Windows versions and doesn't harm system performance at all.
Of course, since it's all so simple, Folder Size also features an “Explore” tool that's placed on the toolbar available in the main window, which does nothing more than to open Windows Explorer and let you browse any location easily.
Another good thing about the program is that it lets you filter the files you browse by format, which means you can see the size of graphics, compressed files, MP3s, music, video or Microsoft Office documents.
All things considered, Folder Size is a handy piece of software, but it still needs a lot of improvements to become a top product in this particular software category. Powerful file managers already offer similar tools, so it's pretty clear that Folder Size's developers have a lot of things to improve.