Check free disk space with df -h

df -h reports capacity, used space, and available space per volume in human-readable units, and on modern macOS it also exposes the APFS Data volume where your real user space lives.

macOSdfdisk-spaceLow risk

Run `df -h` to list all mounted volumes, or `df -h /System/Volumes/Data` for the volume that holds your user data on APFS Macs.

01Command

Command

$ df -h
df -h /
df -h /System/Volumes/Data

02What it does

The -h flag prints sizes in GB/MB instead of 512-byte blocks, and -H uses powers of 1000 like Finder. On Catalina and later, the root (/) read-only system volume shares space with the Data volume through APFS, so the meaningful free-space figure for your files is on /System/Volumes/Data — a detail that regularly confuses people comparing df output to Finder.

03Risk

RiskLow risk

!Warning: APFS volumes in the same container share free space, so per-volume 'available' numbers can mislead; check the Data volume for realistic headroom.

04Undo

✓No undo needed — this command does not change persistent state.

05Sources

df — display free disk space (macOS)
SS64 · technical · 2026-09-17
Evidence: Documents -h human-readable sizes and per-file argument behavior.

Last verified: 2026-09-17 · Category: Files & Folders