Fast Finder
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  1. Fast Finder
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  3. Folder sizes

Fast Finder help

Folder sizes

Fast Finder can show the size of each folder. It counts the items you can see.

Turn folder sizes on

  1. Open Settings (the gear at the top right).
  2. Turn on "Show folder sizes".
  3. Use the Details view. Sizes appear there and are calculated in the background.

What the number counts

  • While "Show hidden and system files" is off, a folder's size counts the visible items only.
  • The tooltip on the size shows how much hidden items add. It reads like: "On disk X. Hidden items add Y (turn on Show hidden to count them)."
  • While Show hidden is on, the size is the whole size.
  • The status bar can also say how many hidden items a folder holds. A click turns on Show hidden.

Show hidden items

  1. Press Cmd+Shift+. in the folder.
  2. Or turn on "Show hidden and system files" in Settings.

This changes the folder view. It does not change search: hidden items are never in search results.

Why a size can differ

  • Fast Finder counts the space used on disk, not the length of the files. Small files take a full block, so a folder can show more than you expect.
  • A hidden folder, such as a .git or .claude folder, can be very large.
  • Get Info (Cmd+I) shows the whole disk use, hidden items included.
  • On Windows, the size is a close estimate from file lengths.