How to check CPU usage on a Mac

To check CPU usage on a Mac, open Activity Monitor and click CPU. The % CPU column shows each process’s share of the processor, and the bottom of the window shows System, User and Idle for the whole Mac. Activity Monitor counts each core as 100%, so one busy app can show far more than 100%.

By the Scope teamUpdated 7 min read

How do I check CPU usage in Activity Monitor?

  1. Open Activity Monitor. It’s in Applications > Utilities, or press Command–Space bar, type Activity Monitor and press Return.
  2. Click CPU at the top of the window.
  3. Click the % CPU column heading to sort the list, busiest first.
  4. Read the bottom of the window for the whole Mac.
Activity Monitor's CPU tab sorted by % CPU, with Blender at 978.6%, Final Cut Pro at 96.4% and Adobe Lightroom at 42.1%, and System 14.60%, User 71.80%, Idle 13.60% at the bottom
Blender is rendering on almost every core. Illustration with made-up readings.

Activity Monitor updates every 5 seconds. A number that jumps for a moment, when an app opens or saves, is normal. A process that stays near the top for minutes is doing sustained work. Which app is slowing down my Mac? covers what to do about it.

Why is CPU usage over 100% on a Mac?

Because Activity Monitor’s % CPU counts each processor core as 100%. A Mac has several cores, so a process working on many of them at once can add up to more than 100%.

MacMost % CPU one process can show
8 cores800%
10 cores1,000%
15 cores1,500%

On this 15-core MacBook Pro, Blender shows 978.6%: the work of almost ten cores. As a share of the whole processor, that’s 978.6 ÷ 15 = 65.2%. About This Mac names your Mac’s chip, and Apple’s Tech Specs page for your model lists its cores: How to check your Mac’s specs shows where.

What do System, User and Idle mean?

The three numbers at the bottom of the CPU tab are shares of the whole processor, and they add up to 100%.

The bottom of Activity Monitor's CPU tab, with System 14.60%, User 71.80% and Idle 13.60% ringed, beside the CPU Load graph, Threads 3,214 and Processes 587
Only 13.60% of the processor is left over. Illustration with made-up readings.
  • System: the share used by processes that belong to macOS (14.60% here).
  • User: the share used by apps you opened, and the processes they opened (71.80%).
  • Idle: the share not being used (13.60%).

So User plus System is your Mac’s total CPU usage: 71.80% + 14.60% = 86.40%. The graph beside them shows the load over the last moments. Below it, Threads and Processes count how many are open.

How do I see CPU usage over time?

Activity Monitor has two small windows for this:

  1. Window > CPU Usage shows the processor’s activity right now.
  2. Window > CPU History shows its recent activity.

Each opens in its own window, so you can keep it beside your work. To change how often the numbers refresh, choose View > Update Frequency. Apple notes that updating more often may affect your Mac’s performance.

Can I see CPU usage in the Dock?

Yes. Activity Monitor’s Dock icon can become a live CPU graph:

  1. Open Activity Monitor.
  2. Choose View > Dock Icon.
  3. Choose the Show CPU option you want.

The icon shows the graph while Activity Monitor is open. To keep it in the Dock, Control-click the icon, then choose Options > Keep in Dock.

How do I check CPU usage in Terminal?

The top command lists processes by CPU use, busiest first.

  1. Open Terminal. It’s in Applications > Utilities.
  2. Type this and press Return:
top -o cpu
  1. Read the line that starts with “CPU usage:”. It splits the processor’s use into user, sys and idle, like Activity Monitor’s User, System and Idle.
  2. Press q to quit top.

Its manual page (man top in Terminal) says -o cpu orders the list by CPU usage, and the display updates every second by default.

Which way should I use?

MethodWhereWhat you seeBest for
CPU tabActivity MonitorEvery process’s % CPU, and System, User, IdleFinding the busy app
CPU Usage windowActivity Monitor > WindowThe processor’s activity right nowA quick look
CPU History windowActivity Monitor > WindowThe last few minutesSpotting what’s lasting
Dock iconActivity Monitor > View > Dock IconA live graph in the DockKeeping an eye on it all day
top -o cpuTerminalProcesses, busiest first, and the CPU usage lineWorking in Terminal

What’s a normal CPU usage on a Mac?

Apple says the processor usually uses only a small percentage of its power, and more when apps need intensive calculation. Apple gives no number for “normal”. What matters is how long it lasts: a burst while an app opens is fine, and a processor busy for minutes, with Idle near zero, is worth a look.

Two macOS processes often look alarming. kernel_task rises when the processor is getting hot, to keep it cool; kernel_task high CPU? explains it. WindowServer draws everything on your screen; WindowServer using high CPU? covers when it works hard.

Questions people also ask

Is it bad if my Mac’s CPU is at 100%?

Not for a while. Exports, renders and builds use every core, and the Mac eases off when they finish. If the processor stays busy for minutes without heavy work, sort the CPU tab by % CPU to find what’s running.

Why does Activity Monitor show high CPU when nothing is open?

Something may be working without a window, such as an app that opens at login, a sync or Spotlight indexing. Choose View > All Processes, then sort by % CPU to see it.

Does Activity Monitor show GPU usage?

Yes. Choose Window > GPU History to see how hard the graphics processor has been working.

How do I check CPU usage on a Mac without Activity Monitor?

Use top -o cpu in Terminal, which lists processes by CPU use and shows the user, sys and idle split at the top.

Scope for Mac · Free, coming to the Mac App Store

How Scope helps

Scope is a free Mac menu bar app that shows your Mac’s CPU use as one number for the whole processor, beside the processes using the most of it and the last few minutes of history. You see how busy your Mac is, and why, without opening Activity Monitor.

In your menu bar

CPU · GPU · RAM shows the live CPU figure in your menu bar, so a busy processor shows before you go looking. Scope Free keeps one whole menu bar item of your choice.

Scope in a Mac’s menu bar: the Scope icon and CPU 86%, GPU 38%, RAM 62%
Scope’s CPU · GPU · RAM panel, opened from the menu bar: CPU 86%, GPU 38%, RAM 62% on Apple M5 Pro, and the tip “CPU usage has stayed high”
Scope sits in your menu bar, and one click opens its CPU · GPU · RAM panel.

One number for the whole Mac

Scope’s CPU figure matches Activity Monitor’s User plus System: 71.80% + 14.60% is about 86%. Its process list shares the whole processor too, so 100% means every core is busy: Blender’s 978.6% on 15 cores is 978.6 ÷ 15 = 65.2%. The list shows the apps you run, not macOS’s background processes such as kernel_task.

Scope’s CPU · GPU · RAM panel: CPU 86%, GPU 38%, RAM 62% on Apple M5 Pro, and the tip “CPU usage has stayed high”Top CPU processes in Scope: Blender 65.2%, Final Cut Pro 6.4%, Adobe Lightroom 2.8%
86% of the whole processor, and Blender using most of it.

The last ten minutes

The chart shows when the load began and whether it’s lasting. Scope Free keeps the last 1, 5 and 10 minutes; Scope Pro keeps 24 hours.

Scope shows and explains. It never quits apps or changes your settings, so what to close stays your call.

Scope's CPU history over 10 minutes: steady around a third, then a jump to about 86% in the last few minutes, with CPU average 46.7% and CPU peak 87.8%
Steady for most of ten minutes, then the render began.
Everything this part of Scope showsMac CPU, GPU and RAM monitor for your menu bar

Try it here

The real Scope, working, right in this page.

Click any item in the menu bar, or a card inside, as you would on your Mac.

Scope Pro Every menu bar item is shown here. Scope Free keeps one whole item of your choice, with every reading inside.

See your own Mac’s CPU at a glance.

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Sources

Last checked October 18, 2026. Readings, apps and files in the pictures are from a made-up Mac.