Check Folder Size on Windows

Your C: drive is full and Windows won't tell you why. DiskLens scans any folder or drive, calculates real sizes for every directory, and shows the space hogs ranked from biggest to smallest.

Why You Need to Check Folder Sizes

When Windows says your drive is 95% full, File Explorer shows you nothing useful. You see Program Files, Users, and maybe a few top-level categories—but not which folder actually holds 60 GB. That 50 GB folder you see? Could be hiding another 45 GB in nested subfolders that never show up in the quick view.

DiskLens walks the entire folder tree, calculates true recursive totals for every directory, and sorts by size. Open it, point it at C:, hit Scan, and within seconds you see exactly which folder to investigate. No guessing, no hunting through File Explorer one level at a time.

How to Check Folder Size in 5 Steps

Download and install Get DiskLens from diskspaceanalyzerpc.com, open the zip, run the installer, and Windows may ask for your permission.
Choose what to scan Press Browse and pick your drive (C:), user folder (C:\Users\You), or any suspicious directory like Downloads or Program Files.
Run the scan Press Scan and wait a few seconds. Large drives take longer the first time, but the tool is light and won't slow your machine.
Read the results The list shows folders ranked by size, largest first. That top entry is your biggest storage consumer.
Drill deeper or clean up Select any folder and scan it again to see what's inside. Once you find the culprit, open it in File Explorer and decide what to delete, move, or archive yourself.

Why DiskLens Works Better Than Windows Built-In Tools

Windows Storage Sense and Disk Management show you categories or a flat list of files. They don't answer the real question: which folder is holding 80 GB? DiskLens does exactly that. It sums every byte in every subfolder, sorts biggest-first, and stops wasting your time.

The tool is read-only—it never deletes, moves, or changes anything. You decide what to clean up in File Explorer afterwards. No risk, no surprise deletions.

It runs offline, no account, no sign-up. Download the zip and run the standard Windows installer. Windows may ask for permission once.

Common Scenarios

**Downloads folder is bloated.** Scan C:\Users\You\Downloads and see what old installers, videos, or archives are eating space. Find the culprits, move them elsewhere or delete them.

**Program Files is huge.** Point DiskLens at C:\Program Files or C:\Program Files (x86) to find which installed apps take the most room. Some games or software suites hide gigabytes in their folders.

**User profile growing fast.** Scan C:\Users\You to spot whether the issue is Documents, AppData, Desktop, or hidden cache folders. AppData can hold hundreds of MB of old app caches.

**Entire C: drive full.** Scan the whole drive and start from the top. Usually you'll find one or two directories responsible for most of the bloat.

Questions

Does it work on Windows 11?

Yes. Windows 10 and Windows 11, 64-bit, both fully supported.

Do I need to be an admin?

Not for everyday scans of user folders and regular drives. Some protected system paths require elevation, but normal sweeps run fine as a standard user.

Does it need internet?

Everything runs locally on your PC. No uploads, no telemetry.

Is it really free?

Yes. Free to download, free to use, open source under MIT. No trial window, no paid tier, no watermarks.