Guide · Windows 11 and 10

How big should your page file be on Windows 11?

The page file is a hidden file Windows uses as overflow and for crash dumps. For most PCs the default is right, and here is how to tell when it is not.

Updated 5 October 2026 · 6 min read

What the page file does

The page file, C:\pagefile.sys, is a hidden file Windows uses as overflow and as a safety net. Programs ask Windows for memory, and Windows promises it. Some of those pages are changed data that exists nowhere else, such as unsaved text in Notepad. If RAM gets tight, Windows can write the least used of those pages to the page file and give the RAM to something more active. Files that already exist on disk, such as .exe and .dll files, are never written to it, because Windows can read them again from their own file.

The page file has a second job: it backs the crash dump Windows writes when it stops with a blue screen. Without enough room for it, no dump is created.

Commit charge: the number that really matters

Microsoft's guidance is that page file size depends on two things that are different on every PC: the crash dump setting and the peak commit charge. Commit charge is the total memory programs have been promised. The commit limit is your RAM plus all page files. If no page file exists, the limit is slightly less than your RAM.

When the charge reaches the limit, Windows cannot promise more, and programs start to fail or Windows warns that it is low on memory, even if some RAM still looks free. To see both numbers, open Task Manager, go to Performance, choose Memory, and read Committed at the bottom (for example 14.2/31.7 GB).

System managed or custom?

By default the page file is system managed, and for most PCs that is the right answer. Per Microsoft, the minimum size depends on your RAM (RAM divided by 8, up to 32 GB), your recent page file usage and your crash dump setting. When commit climbs above 90 percent of the limit, Windows grows the file, up to 3 times your RAM or 4 GB, whichever is larger, and never beyond what the volume allows.

There is no honest one-size rule such as "1.5 times RAM". Choose a custom size only for a reason:

• The system drive is nearly full and you want to cap the file, or move it to a roomier drive.
• You want a predictable size, so the file does not grow and shrink. Set the initial and maximum size to the same value.
• A specific program needs more commit than your RAM provides, and you cannot add RAM.

To size it yourself, watch your peak commit during your heaviest work for a few days. Your RAM plus the page file must stay comfortably above that peak. For example, with 16 GB of RAM and a peak commit of 22 GB, you need at least 6 GB of page file, and 8 GB gives headroom. Then check the crash dump needs below, and use whichever is larger.

Crash dump needs

Microsoft lists the minimum page file for each dump type:

• Small memory dump: about 1 MB.
• Kernel memory dump: depends on how much kernel memory is in use.
• Complete memory dump: your RAM plus 257 MB.
• Automatic memory dump (the default): Windows picks the size. After a second crash within four weeks, it grows the file to your RAM or 32 GB, whichever is smaller.

If you want blue-screen dumps to work, keep a page file on the system drive and do not cap it below the dump type you chose. If you want a dump but no page file, Microsoft's alternative is a dedicated dump file.

SSD or hard drive?

It matters less than people think. Microsoft notes that where the file lives only matters if it is used heavily and the disk is overwhelmed. With several page files, Windows uses whichever responds first, so a faster drive naturally takes more of the work. On a PC with enough RAM, the page file sees little traffic on any drive.

It matters on a hard drive that is already busy. Microsoft's figures: a sustained 100 hard page faults per second is about 400 KB/s of disk traffic, and a 7,200 RPM drive manages roughly 800 KB/s at a 4 KB I/O size. A hard drive that is paging constantly will feel slow, and the cure is more RAM or fewer open programs, not a different page file size.

Why you should not turn it off

• The commit limit drops to just under your RAM, so programs that reserve a lot of memory can fail while RAM is still free.
• Windows cannot write most crash dumps, which makes blue screens harder to diagnose.
• There is no general speed gain to collect. Windows only pages out memory it judges idle, and it then uses the RAM for something useful.

Do not delete pagefile.sys in Explorer. Windows has it open. Change it only through the settings below.

Change the page file in Windows

1. Press Win + R, type sysdm.cpl and press Enter.
2. Open the Advanced tab. Under Performance, choose Settings, then Advanced, then Change under Virtual memory.
3. Untick Automatically manage paging file size for all drives.
4. Select a drive, choose Custom size, enter an initial and a maximum size in MB, and choose Set.
5. Choose OK and restart. To go back, tick the automatic option again.

The crash dump type is on the same Advanced tab, under Startup and Recovery, then Settings.

In Cosmo Cleaner

Release 1.2.0 adds a Memory tab. Its Overview shows commit charge against the limit with a forecast once commit has moved steadily for about five minutes, so you can see your real peak instead of guessing. The Page file and dumps view shows each page file, how full it is, the crash dump type and the clear-at-shutdown setting.

You can keep system managed sizing or set a custom initial and maximum size per drive. Cosmo Cleaner refuses sizes under 16 MB or above the drive's free space, and removing every page file needs an explicit tick box confirming that you understand the risk. Changes need administrator rights, apply at the next restart, and record the previous value so Undo in Vault and undo puts it back.

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