PieSize

PieSize is a feather-light and portable application that automatically calculates disk space distribution to reveal the largest folders in a pie chart. It lets you pick the target drive and analyze any errors.

No installation required

You can save the program files in any part of the hard drive or a USB flash disk and just click the executable to launch the tool. Otherwise, you can keep it stored on a USB flash disk to be able to directly run PieSize on any computer with minimum effort and no previous installers. It doesn't make any modifications to the Windows registry.

Simple UI for drive scans

Adopting an outdated interface, the utility has a simple window that shows all options available, enabling you to pick the directory whose subdirectories you want to quickly computer.
Results are displayed in descending order by size, and you can examine the legend to figure out how the items are distributed on the chart, in addition to the total and used partition space.

Find out largest folders and subfolders

The tool can be instructed to recalculate everything. An error example is read access denied on specific paths, which prevents the program for scanning the folders in question. It's also possible to visit the drive in your default file explorer, as well as to dig deeper within the drive to view pie charts with subfolders in any directory.
Unfortunately, there are no options implemented for copying pie charts as images or file lists as text, printing, or exporting data to file. We must also take into account that it hasn't been updated for a long while.

Evaluation and conclusion

It conducted drive scan operations swiftly in our testing while using low system resources. No error dialogs popped up and it didn't freeze or crash. However, it's an old app with no options for exporting data. Nevertheless, PieSize offers a simple solution for calculating disk space to find out the largest folders.