CPU temperature, CPU usage and memory on a Mac: where to look, and what's normal

CPU usage: Activity Monitor

1. Open Activity Monitor: Applications › Utilities, or press ⌘ Space and type its name.
2. Click CPU, then click the CPU percentage column heading to put the busiest processes on top.
3. At the bottom of the window, read the split: System (macOS), User (your apps) and Idle (unused capacity).
4. To keep an eye on it, choose Window › CPU History, or View › Dock Icon to show CPU activity in the Dock icon.

Most of the time, a Mac uses only a small share of its processor. Apple's own advice: if a laptop runs warm during light tasks, look in this tab for a process that has run away. In Terminal, top -o cpu gives the same list, sorted.

Memory: read the pressure, not the free memory

In the Memory tab, the bottom of the window sums it up. The definitions are Apple's:

• Memory Pressure: a graph of how efficiently memory is serving your needs. Green, the Mac is using all its RAM efficiently; yellow, it might eventually need more; red, it needs more.
• Memory Used, including App Memory (used by apps) and Compressed (compressed to make more RAM available).
• Cached Files: files kept in unused memory to speed things up. That memory is released as soon as an app needs it.
• Swap Used: space on your startup disk used to swap memory to and from RAM.

Memory that's almost fully used isn't a problem: according to Apple, macOS gets its best performance by using all of it. And the pressure already accounts for free memory, the swap rate, wired memory and cached files: as long as it stays green, some swap is nothing to worry about. What should get your attention is pressure that stays yellow or red while swap keeps growing. Close the hungriest apps and tabs; if it happens every day, the Mac doesn't have enough RAM for what you do. To see whether yours can take more (only a few models can), hold Option and choose Apple menu › System Information, then Memory.

In Terminal, memory_pressure prints the system-wide free memory percentage, and sysctl vm.swapusage shows swap in use.

CPU temperature: why macOS doesn't show it

Activity Monitor has no temperature column, and neither does System Settings. Apple sticks to three points:

• use a Mac laptop where the ambient temperature is between 10° and 35° C (50° to 95° F);
• internal sensors watch the heat, and fans, on Macs that have them, turn on automatically;
• third-party apps that measure temperature don't measure the external case, which is much cooler, and should never be used to diagnose hardware issues. For that there's Apple Diagnostics: on an Apple silicon Mac, press and hold the power button until you see the startup options, then press and hold ⌘ D.

What Terminal can tell you

1. pmset -g therm: no password needed; tells you whether macOS has recorded a thermal or performance warning. "No thermal warning level has been recorded" means there hasn't been one.
2. sudo powermetrics --samplers thermal -n 1: after a few seconds, prints a "Current pressure level" line, for example "Nominal". That's thermal pressure, not a temperature.
3. On Intel Macs only, sudo powermetrics --samplers smc used to show the "CPU die temperature". On Apple silicon the tool has no such sampler: the command answers "unrecognized sampler".

macOS rates its thermal state on four levels that apps can read: nominal, fair, serious and critical. At critical, performance is significantly reduced while the machine cools down.

What's a "normal" temperature on an Apple silicon Mac?

Apple publishes no limit for its M chips: they're designed to protect themselves, by spinning up fans and then slowing down. A high number under heavy load isn't a fault in itself. To give you an order of magnitude, here's what we measured on the fanless MacBook Air M4 used to build Tack+'s Monitor: about 53 °C (127 °F) on average across the cores outside of any build, and up to 100 °C (212 °F) during a long compile.

Same Mac, same moment, the so-called "PMU tdie" sensors, which belong to the power management circuit, read 41 °C, then 57 °C during the compile. That's why two apps often show different temperatures: they don't read the same sensors. An app that averages those probes shows a lower, misleadingly reassuring number under the word "CPU".

What does deserve attention: a thermal state that leaves "Nominal" during light work, a fan that roars for no reason, or heat with no visible activity in Activity Monitor. Then find the process responsible, and run Apple Diagnostics.

Menu bar and widget monitors

Stats, iStat Menus and TG Pro live in the menu bar, with one or more icons per measurement. On a notched MacBook that bar is shorter: icons that no longer fit slide behind the camera, still running but out of sight (see menu bar icons hidden behind the notch). If that happens, show fewer measurements, or pick a monitor that stays out of the bar until you open it: that's the idea behind the notch panels compared in our Dynamic Island for Mac guide, Tack+ among them.

Prices checked on September 27, 2026 on the developers' sites, in US dollars before tax; they may have changed since.

Tack+'s Monitor widget

Tack+ tucks your Mac into a thin line at the edge of the screen, and its home takes widgets. Monitor ("Processor and memory") shows at a glance what this article sends you to three places for:

• Processor: the activity percentage and its curve over the last minute, plus one bar per core, performance and efficiency cores apart.
• Temperature: the average of the core sensors, the hottest one, and how many sensors were read. When the Mac exposes no readable sensor, the widget shows the macOS thermal state (Normal, Slightly elevated, Elevated, Critical) and says it isn't a measurement.
• Memory: used out of total, its pressure (ivory when normal, amber then coral as it rises), the share of apps, wired, compressed and cached memory, and swap.
• The rest: free disk space, battery, how long the Mac has been on, and fans when it has them. Degrees switch to Fahrenheit if your Mac is set that way.

To add it: in the panel's tools row, click Rearrange the home, remove a card with "−", click "+" in its place, then choose Monitor. The widget reads nothing while the panel is closed: one reading every two seconds while it's on screen, every four in Low Power Mode. A button opens Activity Monitor when you need to dig deeper.

What it doesn't do: it doesn't control fans, quit processes, or keep history beyond the last minute. The other widgets in the gallery are covered in our guide to widgets on Mac; on a notched MacBook, the panel sits against the camera, as the notch guide explains.

Sources: Apple Support, View memory usage in Activity Monitor, Check if your Mac needs more RAM and Keep your Mac laptop within acceptable operating temperatures, accessed September 27, 2026; commands checked on macOS 26.