Memory Used shows more RAM than physically installed

Your report shows a normal healthy Mac memory profile.

"Memory Used' became an obsolete metric for Macs 13 years ago (!). Current performance metrics are Memory Pressure and Swap Used. Pressure should be green—like yours— and Swap should be under 500MB—again like yours. Yours passes the test.

Swap is a measure of how much data must be temporarily written to the drive when physical memory is stressed. At the time of your screenshot showing 0 Swap, your physical RAM was handling everything just fine, not even breathing hard.

I'm not clear as to which numbers you are using. Are you adding Memory Used plus Cached? Caches are typically stored on the hard drive, not as part of the 24 GB "RAM". Your actual "RAM" used is 16.65.

Note that memory on modern Macs is not apportioned the same way it was on older Macs. You may also wish to read this 2026 discussion about Mac memory and cache.

https://discussions.apple.com/thread/256223313

Haito_Worl wrote:

As you can see, my Memory Used is almost 4 GB above the sum of all the processes listed, and this results in me apparently having over 25 GB of Memory on a 24 GB machine? What's going on here?

https://discussions.apple.com/content/attachment/3f8e248f-ab3a-42db-9154-77fbafea2af0

Not sure what your concern is.

https://support.apple.com/en-bn/guide/activity-monitor/actmntr1004/mac

I'm wondering if activity monitor is reliable, since it's consistently showing memory usage that's impossible from my understanding. Of the three numbers its shows (24 GB installed, 16.65 GB used, 8.89 cached), at most two of them can be accurate. My concern is that I don't know which two.

Possibly the readings were not all calculated “instantaneously”, within a single atomic transaction.