---
title: "Mac memory usage explained: vm_stat to GB, free tool"
description: "Paste vm_stat from Terminal to see your Mac’s memory in GB the way Activity Monitor groups it: app memory, wired, compressed, cached files, free and swap."
url: https://tidymac.space/tools/mac-memory-usage/
updated: 2026-10-16
---

[Home](/) [Tools](/tools/) Mac memory usage explainer

# How much memory is my Mac really using?

Memory used on a Mac is app memory + wired + compressed. Cached files look “used” but are freed the moment an app needs them. Paste `vm_stat` below to see your numbers in GB.

Updated October 16, 2026By the Tidy Mac team

1\. Run this in Terminal

```
vm_stat
```

2\. Paste the output

vm\_stat outputMach Virtual Memory Statistics: (page size of 16384 bytes) Pages free: 12034. Pages active: 301233. Pages inactive: 288876. Pages speculative: 4410. Pages wired down: 152003. Pages purgeable: 9412. File-backed pages: 231190. Anonymous pages: 363329. Pages occupied by compressor: 98101. Swapouts: 0.

**9.22 GB**memory used

**3.67 GB**cached files (reusable)

**No**swapped to disk since startup

**App memory**

5.4 GB

Used by apps right now

**Wired**

2.32 GB

Kept by macOS, can’t be compressed

**Compressed**

1.5 GB

Idle memory squeezed to save room

**Cached files**

3.67 GB

Reusable, freed instantly when needed

**Free**

0.18 GB

Not used at all

![](/img/brand/tidy-128.png)

### Short on disk space as well?

Tidy Mac leaves memory to macOS, which manages it well. It finds the disk space your Mac is hiding, System Data included; a nearly full disk is what makes swap hurt. $9.99 once, 2 Macs.

[Download](/download/TidyMac.dmg) [Buy for $9.99 once](/buy/)

## How it works

`vm_stat` counts memory in pages. The checker multiplies each count by the page size in the first line (16 KB on Apple silicon, 4 KB on Intel) and groups them like Activity Monitor:

-   **App memory** ≈ anonymous pages − purgeable pages.
-   **Cached files** ≈ file-backed pages + purgeable pages.
-   **Memory used** = app memory + wired + compressed.

Activity Monitor’s figures can differ slightly; these are close approximations from the same counters. Running out of disk space can also cause swap trouble: see [what /private/var/vm is](/folders/private-var-vm/).

## Questions

How do I check memory usage on a Mac?

Open Activity Monitor › Memory for the graph and Memory Pressure. In Terminal, `vm_stat` prints the raw page counts; paste them here to get the same groups in GB.

Is it bad that my Mac uses almost all its RAM?

No. macOS keeps recently used files in memory (Cached Files) and compresses idle memory instead of leaving RAM empty. What matters is memory pressure and swap: if pressure is green and swap stays low, you have enough.

What is compressed memory?

Memory that macOS squeezed to make room, which is faster than writing it to disk as swap. Some compression is normal; lots of it plus growing swap means you’re short on RAM.

Can a cleaner “free up RAM”?

Not usefully. macOS manages memory itself, and forcing caches out just makes apps reload them. Quit apps you don’t need instead.

## Related

[What is swap?Glossary](/glossary/swap/)[What is /private/var/vm?Folder](/folders/private-var-vm/)[Mac running hot?Guide](/guides/mac-running-hot/)[Mac battery health checkerFree tool](/tools/mac-battery-health/)[Find large files commandFree tool](/tools/find-large-files-mac/)[How much storage do I need?Free tool](/tools/mac-storage-needed/)