# Why MoreRoom’s numbers differ from Finder and System Settings

> Purgeable space, local snapshots, APFS clones, size on disk vs logical size, hidden folders and GB vs GiB: why each tool shows a different number.

- URL: https://moreroom.app/support/numbers-differ
- Topic: Troubleshooting
- Updated: 2026-10-17
- Publisher: MoreRoom (Yando Pte. Ltd.) — https://moreroom.app

## In short

- Available space includes purgeable space — caches and snapshots macOS deletes on its own when it needs room. MoreRoom shows it separately, as Finder does not.
- MoreRoom measures what files really take on disk. Shared copies (APFS clones) and compressed files take less than their logical size; Finder adds full sizes.
- Like Finder, MoreRoom uses decimal units (1 GB = 1,000,000,000 bytes). Terminal and some apps use binary units (GiB), which look about 7% smaller.

## Free space: three different answers

| Where | What it calls free |
|---|---|
| **Finder**, **System Settings › General › Storage**, MoreRoom’s home screen and header (“available”) | Free space **plus purgeable space** |
| Terminal’s `df`, MoreRoom’s **Locations** list in the sidebar | Free space **only** |
| MoreRoom’s header, next to “available” | “*size* purgeable”, when there’s more than 100 MB |

**Purgeable space** is space macOS promises to give back on its own when it needs room: caches, local Time Machine snapshots, iCloud files it can download again. It counts as available because you can use it — but it isn’t empty yet. Our guide [Purgeable space on a Mac](https://moreroom.app/learn/purgeable-space-mac) explains it in detail.

## Size of a folder

MoreRoom shows the **space a file really takes on disk**. Finder’s **Get Info** shows two numbers, and other tools may add sizes differently:

- **APFS clones** — for example copies made with Finder’s Duplicate — share their data. MoreRoom counts shared space once; Finder counts each copy in full. The inspector says **APFS clone — Shares space with a copy**. [Free Without Deleting](https://moreroom.app/support/free-without-deleting) turns identical files into such clones.
- **Compressed files** — including cold files compressed by Free Without Deleting — take less than their **Logical size**, which the inspector also shows.
- **iCloud files only in the cloud** take almost nothing on your Mac (“Only in the cloud”), even if Finder shows their full size.
- **Hard links** are counted once.

## The scan total is smaller than the space used

- **Without Full Disk Access**, protected folders are skipped. See [Grant Full Disk Access](https://moreroom.app/support/full-disk-access).
- **Some folders need admin access** (system caches, other users), and **local snapshots** and file system metadata aren’t files you can see. Scan your Mac, then open [System Data, explained](https://moreroom.app/support/system-data-screen): it shows this hidden part as **Not visible without admin access**.
- **macOS’s own volumes** (sealed system, Preboot, Recovery, virtual memory) are outside your data.
- Folders in **Settings › Exclusions** are not scanned.

## GB or GiB?

MoreRoom, like Finder and System Settings, uses **decimal units**: 1 GB = 1,000,000,000 bytes. Terminal tools such as `du -h` and some apps use **binary units** (GiB, sometimes written “G” or even “GB”): 1 GiB = 1,073,741,824 bytes. The same folder looks about 7% smaller in GiB. Try our [GB vs GiB converter](https://moreroom.app/tools/storage-units-converter).

## Numbers that change after a cleanup

Items moved to the Trash still take space until you empty it, and an app may keep deleted files open. See [Space didn’t come back](https://moreroom.app/support/space-not-back).

## Related articles

- [Understand System Data with MoreRoom](https://moreroom.app/support/system-data-screen.md)
- [I removed files, but my free space didn’t come back](https://moreroom.app/support/space-not-back.md)
- [Explore your disk: map, rings, list and inspector](https://moreroom.app/support/map-rings-list.md)
- [Grant Full Disk Access to MoreRoom](https://moreroom.app/support/full-disk-access.md)

## Still need help?

Write to us: a real person reads every message and answers within 2 business days. https://moreroom.app/contact