macOS Monterey Storage requirements-- confused

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Level 1

4 points

macOS Monterey Storage requirements-- confused

I'm currently running High Sierra (10.13.6) on my MacBook Air (13-inch, Early 2015). I need to upgrade to use Office 365 and some other apps.

On the AppStore listing for Monterey it says the size is 12.13 GB. When I try installing Monterey, it shows I have 19.81GB available of 121.12GB. Then it refuses to let me install, saying I need an additional 23.76GB.

Wait, what? I'm down with thinking Different-- but am having difficulty understanding how 12 is now 23 more than 19. Can someone help please help? Thanks much!

Joe

Posted on Nov 16, 2021 4:21 PM

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Answer 1

dialabrain

Level 10

136,667 points

Nov 16, 2021 4:44 PM in response to tenor11

The bottom line is, If upgrading from macOS Sierra or later, your Mac needs 26GB of available storage to upgrade. If upgrading from an earlier release, your Mac needs up to 44GB of available storage.

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Answer 2

Barney-15E

Level 10

123,122 points

Nov 16, 2021 4:40 PM in response to tenor11

The final size of the OS is about 16GB. The installer must move things around when installing the new OS, so it takes a lot more than the final size of the installed OS.

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Answer 3

etresoft

Level 9

57,476 points

Nov 16, 2021 4:39 PM in response to tenor11

tenor11 wrote:

Wait, what? I'm down with thinking Different-- but am having difficulty understanding how 12 is now 23 more than 19. Can someone help please help? Thanks much!

Yes. It's quite simple. Your computer is lying. Or rather, your computer is telling the truth, but in an extraordinarily precise way that depends entirely on context. When macOS reports storage as "available", that means that there is some complicated background process running that could, at some underdetermined time in the future, make that amount of currently allocated storage "available" for your use, should it actually decide to do so. Until then, you have 760 MB of free storage. Enjoy!

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macOS Monterey Storage requirements-- confused

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