■ Folder size calculation and plugins

Size column doesn't normally show any information when folders are concerned, it just unhelpfully says <folder>. Calculating the size occupied by a folder is time consuming as all the contained files must be added up recursively into all subfolders — which can be many levels down in case of root folders.

Use Tools > Subfolder size menu to calculate and show folder sizes. The information is extracted in the background but it may take some time, so please be patient.

If you prefer file and folder sizes rounded in KB/MB/GB, untick the program option Size in bytes

To spare your CPU and disk resources and calculate only particular subfolder sizes, select the folders in question beforehand. Then <CTRL+D> command will only calculate sizes for selected folders. If you want to see sizes for all folders, tick the advanced option "Calculate subfolder size for all items..."

Except for on-demand, you can turn on continuous folder size calculations turning on Subfolder size program option. This option is not recommended if you have any modicum of machine sympathy <g> but if you do enable it keep in mind that it won't work when browsing the following types of folders:

Root folders. Top level folders like C:\ — where the effort would be maximal — won't be calculated. To see folder sizes there (under continuous size policy) you must press <CTRL+D> twice, or install Kilmatead's plugin (see further down).
Network folders. Remote folders, be it root or otherwise, will not be calculated unless you tick off Faster networks setting from Tools > Options menu (Advanced category).
Zipfolders and phones. Continuous folder sizes are suspended when you browse such non-filesystem folders. Only on-demand sizes are supported.

Speed improvements using plugins

xplorer² doesn't cache any folder size calculations. Each time you return in some folder, its subfolders are calculated afresh, testing your patience in pursuit of your anorak information thirst. Things can be substantially improved if you install specialized folder size plugins that maintain a cache and avoid unnecessary disk access.

The first one is the (abandonware) Folder Size shell extension. This will install an [X] column called Folder size which you can find and activate using View > Select columns menu command. You can turn off continuous folder size calculation in xplorer² and use this extra column for subfolder data.

Don't install the latest version 2.6, go for the previous v2.5 linked above. Foldersize author tried some funky separate window solution to circumvent the demise of column handlers brought about by Vista. v2.5 incorporates as an internal xplorer² column and is preferred.

Kilmatead's SizeES plugin

Our recently resurrected star forum member Kilmatead has written a plugin that incorporates Everything search index size information and makes it available straight in Size column — no need to select a separate folder size column. Here are more details in his master's unique prose style. In abbreviation, here's the gist of it:

You must install and run Everything as a background service
Download and install SizeES WDX plugin (see below).
Turn on continuous subfolder size option

Due to our combined effort, SizeES shows folder size information even in root folders without extra effort!

Click to download SizeES plugin (180 KB)

Download and unzip the file, and use the WDX plugin helper to enable it in xplorer².

However you look at it, all this effort seems overkill; do you weigh yourself every five minutes? Are you afraid that your files will develop a cancerous growth and overwhelm your hard disk? But I digress... who am I to stand between a man and his fetishes? <g> Enjoy!