The small jobs that should already be easy are the ones I judge a desktop operating system by. Windows 11 has been nagging me for years about its inability to show me how big a folder is in the same list view where it shows me how big every other file is. The detail dialog has the answer. The right click menu has the answer. The column I want does not. That gap between the question I am asking and the answer Windows is willing to give is small enough that most users just live with it, but it shows up exactly when I least want it to, which is when my drive is nearly full and I am trying to figure out which folder to clean out.
What File Explorer actually shows you
Open File Explorer in Details view and create a folder. Drop a few files into it. The individual files in the list will show their size in the Size column. The folder you just created will show a blank Size column. The same thing happens for every folder you have ever made on the drive. The reason is straightforward. Windows treats the Size column as a property of file entries, not of folder entries, and it does not compute the sum of a folder’s contents to fill in the value. The folder’s blank Size is not an indication that the folder is empty. It is an indication that Windows has not done the work to tell you it is not empty.
The result is a list view that is half complete in the worst possible way. You can see exactly which files are large and which are small. You cannot see which folders are large and which are small. The thing you actually want to know when your drive is filling up is which folders are taking up space, and Windows is not willing to give you that information in the place you would look for it.
Why the detail dialog is not a real answer
Windows can absolutely compute a folder’s total size. You can see this yourself by right clicking any folder, choosing Properties, and waiting for Windows to finish calculating. The total appears in a small dialog that you then have to close, and the value disappears as soon as you click away. This is technically a way to answer the question, but it is not a workable answer if you are trying to compare several folders to figure out which one is hogging space.
The comparison flow is the real problem. To compare five folders by total size, you have to right click the first folder, open Properties, read the number, close Properties, right click the second folder, open Properties, read the number, close Properties, and so on. By the fourth folder you have lost track of which number belonged to which folder. By the fifth folder you have given up and opened a third party tool that you should not have needed to install in the first place. A Size column in the main list view would let you sort by size and find the largest folder in two clicks. The Properties dialog makes the same task a multi minute chore.
There is a defensible engineering reason for the current behavior. Computing a folder’s total size requires Windows to scan the folder, which can be slow for folders with many files. Recomputing that total on every view of the folder would make File Explorer feel sluggish, especially on machines with large media libraries. The trade off is reasonable in the abstract. The problem is that Windows has made the choice for the user without giving the user the option to override it, and the default choice is the wrong one for the people who actually care about folder sizes.
Where the gap shows up most
The gap matters most when the drive is close to full. At that point you are not browsing for entertainment. You are trying to free up space, and the question you need answered is which folder is taking up the most. Without a Size column, that question takes minutes to answer through the Properties dialog, and minutes is exactly the kind of friction that pushes users toward installing cleanup utilities they do not need.
A second place the gap matters is when you are trying to decide whether to move or archive a folder. The decision often depends on the size. A folder that is 200 MB might be worth keeping in place. A folder that is 80 GB probably should move to an external drive. Without a Size column, you cannot even begin the calculation without opening five Properties dialogs in a row. The friction adds up.
A third place is when you are auditing storage for someone else. If you are helping a less technical user figure out why their drive is full, you want a column that answers the question directly. The current behavior forces you to walk the user through a multi step process that involves right clicking, waiting, reading, and remembering. That is a poor experience for the user, and a worse one for the helper.
A workaround that actually works today
Until Microsoft adds a proper Size column to File Explorer, the practical workaround is to use the Properties dialog and accept the friction. The order I would use when trying to free up space:
- Start with the folders you actually use. Downloads, Documents, Desktop, and Pictures are usually the largest sources of growth on a personal machine.
- Right click each candidate folder and open Properties. Wait for the size to calculate. Note the number, ideally in a text file or a note, because the value disappears as soon as you close Properties.
- Sort the candidates by size and act on the largest first. A 40 GB Downloads folder is a bigger win than a 2 GB Documents folder, even if Documents feels more cluttered.
- Move or archive what you can, then delete what you do not need. Free space on the boot drive matters more than free space on a secondary drive.
That workaround gets the job done. It should not be confused with a good default experience, because the operating system is already capable of computing the value, and the only thing standing between the user and the answer is a UI decision that could be reversed tomorrow without changing any underlying capability.
Trade-offs
Adding a Size column to File Explorer is not free in compute. The size calculation requires a scan of the folder, which can be slow for folders with tens of thousands of files. Microsoft would have to decide whether to compute sizes eagerly (every time the folder is shown), lazily (on demand when the user clicks the column header), or as a background job. Each approach has tradeoffs around responsiveness, accuracy, and resource use on the user’s machine.
It is also not free in design complexity. The current Details view is already crowded with columns. Adding Size for folders would mean either widening the column area, hiding the value for empty folders, or computing it asynchronously with a placeholder while the calculation runs. None of those options is hard, but each one adds UI surface that has to be designed, tested, and shipped.
And there is the third party tool world to consider. Tools like WinDirStat, TreeSize, and Folder Size have filled this gap for years, and some users rely on them as part of their normal storage workflow. Microsoft adding a built in Size column would reduce the appeal of those tools, which is fine for users but is a small commercial disincentive for the company to ship the feature.
Bottom line
Windows 11 can show folder sizes in File Explorer. The fact that it does not is a UI choice, not a capability limit, and it is the wrong choice for the people who need the answer most. Until Microsoft adds a proper Size column to Details view, the Properties dialog is the practical workaround, but it is also evidence that one of the most ordinary tasks on a desktop operating system is still harder than it needs to be. If you only do one thing this week, audit your largest folders using the Properties dialog and write down the numbers. The friction will be obvious within five minutes.