See CPU usage in your Mac menubar

Your Mac feels warm, the fans just kicked in, and you want to know if something is actually hammering the CPU — without dragging Activity Monitor across every Space you’re in. macOS doesn’t put CPU usage in the menu bar by default, and that’s a strangely big gap for a power-user OS.

Here are the two ways to get a permanent CPU readout up top.

Two paths

The native way (Activity Monitor)

Activity Monitor can show a live CPU graph in the Dock, but not the menu bar. Open Activity Monitor, then View > Dock Icon > Show CPU Usage (or Show CPU History for the rolling graph). That gives you a tiny live chart bolted to your Dock icon.

The catch: you have to leave Activity Monitor running, the Dock has to be visible, and the icon is small. You can also pop a floating CPU window via Window > CPU Usage — same problem, it floats in front of your work.

If you want numbers in Terminal instead, top -o cpu gives you a live process list sorted by CPU. Useful for a one-off check, less so as ambient awareness.

The Beacon way

Beacon puts a live CPU percentage (or bar, or graph — your pick) directly in the menu bar, where it stays visible no matter what app you’re in.

1. Install Beacon and grant it the permissions it asks for on first launch.
2. Click the new Beacon icon in your menu bar to open the panel.
3. In Settings > Menu Bar, tick CPU to add it to the bar.
4. Pick your display style — percentage, mini bar, or sparkline graph.
5. Click the CPU readout any time to see a per-core breakdown and the top CPU-using processes.

That’s the entire setup. Beacon updates roughly once a second and uses a trivial amount of CPU itself (under 1% on Apple Silicon in my testing).

A small tip: if you’re on a notched MacBook and your menu bar is crowded, switch Beacon’s CPU display to just the percentage number — it takes maybe 30 pixels and you stop fighting the notch.