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Calculating folder sizes simplified

Microsoft Explorer won't calculate the size of a folder unless you specifically ask for it, and the process of calculating a folder size can take a long time. But there are third-party programs that allow you to obtain this information more easily.

With Windows Explorer, it's hard to get an idea of how big a folder in a given directory is. When you open Explorer and look at the Details view of a folder, the Size column is empty.

Part of the reason for this is because Explorer won't calculate the size of a folder unless you specifically ask for it (by right-clicking a folder and selecting Properties), and the process of calculating a folder size can take a long time since it has to recurse through each subfolder and determine its contents to get an accurate count. Evidently Microsoft elected to only show this information "on demand" because of the effort involved to obtain it. But many people have asked me if there's a way to obtain it a bit more easily.

One of the simplest ways to do this is to install Folder Size, a free, open-source utility that integrates directly with Explorer, so there's no need to click anything or run an external program. Once you've installed it, you can add a Folder Size column to Explorer that lists the size of the underlying folders in a view. The size of each folder is tabulated passively in the background; if a given folder's size is still being tabulated, you'll see a + sign next to the folder size.

Other columns include "File Children" and "Folder Children", which list how many files and folders are available under that particular folder. The program also adds a Control Panel entry to let you control its underlying behavior, including stopping or resuming the folder size cache service. This allows the sizes of folders to be tabulated and maintained consistently, so they only need to be reindexed when the contents of a folder change. The overhead on the system for doing this is minimal.

I've also looked at a few standalone applications. TreeSize harvests the same kind of information from the folders on any system drive, but it has one drawback: On a system where there are a great many folders (such as my own music drive, which has something like 80GB of ripped music), the program's interface sometimes stalls and doesn't return any progress feedback.

One program which is striking both for the kinds of results it returns and the way it's been implemented is DirLot, a compiled HTML application that returns a colorful and interactively explorable folder-size report. The program is designed to tell you what in a given directory is taking up the most space by percentile, but it also returns the total size of a given folder quite quickly, and it tries to inform the user when it's busy harvesting information so you're not faced with an inactive display when you click on something.

All the programs described above (except for TreeSize) have one drawback: They can't produce printed reports. If you want a simple command-line program to return the total size of folders in a simple text report, check out TreeInfo, which can be used to pipe its results to a text file. One of the sample uses listed in the program's documentation involves the SORT command.

About the author: Serdar Yegulalp is editor of the  Windows Power Users Newsletter, which is devoted to hints, tips, tricks, news and goodies for Windows NT, Windows 2000 and Windows XP users and administrators. He has more than 10 years of Windows experience under his belt, and contributes regularly to and

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