Freeing up space · One-tap clean-up (Run Tuhi)
How does Storage Studio work out how much space a Run Tuhi clean-up freed?
Short answer: Storage Studio measures your Mac's free space just before and just after the run and reports the difference — the same figure the storage chart shows — rather than adding up estimates.
It's measured, not added up from guesses. Storage Studio reads your Mac's free space just before the first step and again just after the last, and reports the difference — the same free-space figure the storage chart and the popover show, so the two can't disagree.
That means anything that genuinely leaves your built-in drive (deleted caches, folders moved to your fast drive) is counted, and anything that only reshuffles space your Mac already treated as available isn't. If you were saving files during the run, the result reflects that too.
Old local backups that were tidied are reported on a separate line — see why they aren't counted as freed.