Folder Size Explorer is similar to Windows Explorer except it calculates folder sizes. Folder Size Explorer calculates folder sizes as you browse them and allows you to quickly indentify directories on your hard drive or network that are consuming the most disk space. It can also calculate checksums (MD-5, SHA-1 and SHA-256) of all files and can export Windows Explorer folder and file lists to csv files.
Folder Size Explorer provides almost all the functionality of the standard Windows Explorer and runs on both x86 and x64 versions of Windows 7, 8, Vista, XP and all versions of Windows Server 2003, 2008, 2012. Folder Size Explorer is freeware.