Guide
How to see fan speed on a Mac, and why Apple Silicon fans rarely spin
Macs are quieter than they used to be, and that makes people nervous: a MacBook Pro at 95 °C with the fans at 0 rpm feels wrong, but it is exactly how Apple designed it. This guide covers which Macs have fans at all, how to read the fan speed, what numbers are normal, and what fan control software can and cannot do.
Which Macs have fans
| Mac | Fans | Notes |
|---|---|---|
| MacBook Air (M1 to M4) | None | Passive cooling. Throttles under long heavy loads instead of getting loud. |
| MacBook Pro 14-inch and 16-inch | Two | Stop completely when cool; usually silent until the chip is well into the 90s. |
| MacBook Pro 13-inch (M1, M2) | One | Same behaviour, one fan. |
| Mac mini | One | Spins slowly all the time at a very low speed. |
| Mac Studio, iMac, Mac Pro | Two or more | Always spinning, rarely audible. |
If you have a MacBook Air, nothing in this guide applies except the last section: there is no fan to read.
How to see the fan speed
Terminal (free, built in)
sudo powermetrics --samplers smc -i 1000 -n 1
On a Mac with a fan this prints the current fan speed in rpm under "SMC sensors". It takes one reading and exits. It is fine for a quick check and useless for watching a trend.
Free apps
- Macs Fan Control shows every fan and every temperature sensor and is free for monitoring. The paid Pro version adds custom fan curves.
- Stats (open source) has a fan module for the menu bar.
Paid apps
- iStat Menus ($11.99 one-time) shows fan speed in the menu bar and includes fan control rules.
- TG Pro is built around temperatures and fans and is the most complete fan control tool on the Mac.
- ThermPort (ours, $9.99 one-time, $6.99 at launch) shows fan speed as rpm or as a percentage of the fan's maximum, next to temperature, CPU, memory and seven other metrics, with a live chart. It is read-only and does not change fan speeds.
What fan speeds are normal
On the 14-inch and 16-inch MacBook Pro the fans sit at 0 rpm most of the day. When they do start they run from roughly 1,500 rpm at the low end up to around 6,000 to 7,000 rpm at full speed depending on the model, and you will hear them clearly from about 3,000 rpm. Mac mini and desktop fans idle at a low constant speed that you should not be able to hear in a quiet room. Exact figures vary by model, so if an app shows a percentage of maximum, that is the easier number to read: 0% is off, 100% is as loud as it gets.
Why Apple Silicon fans rarely spin
Two reasons. First, the chips use far less power than the Intel parts they replaced, so there is less heat to remove in the first place. Second, Apple tuned the fan curve to accept high chip temperatures rather than noise: the fans are not asked to do anything until the die is well into the 90s, and the metal chassis spreads enough heat for everyday work on its own. The result is a Mac that runs at temperatures that would have had an Intel MacBook roaring, in silence, by design. If you want the chip cooler at the cost of noise, that is what fan control software is for.
Fan control: what it can and cannot do
Fan speed is set by the System Management Controller. Apps that change it, such as TG Pro and Macs Fan Control, write custom curves to the SMC through a privileged helper, which is why they ask for an administrator password. They can make the fans start earlier or run faster, which lowers temperatures and shortens the time the chip spends throttled under sustained load. They cannot make a MacBook Air grow a fan, and they cannot push a fan past its hardware maximum. Monitoring-only apps, including ours, deliberately stay read-only: reading the SMC is harmless, writing to it is a different kind of software.
When fan behaviour points to a problem
- Fans at full speed while the Mac is cool and idle. Check Activity Monitor for a busy process first; if there is none, suspect a sensor or fan fault.
- 0 rpm while the temperature climbs past 100 °C under load on a MacBook Pro. The fan may have failed. Apple Diagnostics will confirm it: shut down, hold the power button until startup options appear, then press Command-D.
- A rattling or grinding noise. Dust in the blades or a worn bearing. A clean-out usually fixes the first; the second needs a replacement fan.
For the full list of reasons a Mac gets loud and how to fix each one, see MacBook running hot and fans loud.
Frequently asked questions
Why does my MacBook Pro show 0 rpm fan speed?
Since the 2021 redesign the MacBook Pro fans stop completely when the chip is cool, and Apple's fan curve keeps them off until the chip is well into the 90s. 0 rpm at idle and during light work is normal.
Does the MacBook Air have a fan?
No. Every Apple Silicon MacBook Air is fanless and cools passively. Under a long heavy load it slows itself down instead of spinning anything up.
Is 6,000 rpm bad for a Mac fan?
No. That is roughly full speed on a MacBook Pro and it is what the fan is for. It only deserves attention if it happens while the Mac is idle and cool.
Can I make the fans come on earlier?
Yes, with a fan control app such as TG Pro or Macs Fan Control, which write custom fan curves to the SMC. Monitoring apps like Stats, iStat Menus and ThermPort read the speed but most do not change it.
ThermPort puts CPU temperature, fan speed, memory, power and more in your Mac's menu bar in a 15 MB app. 14-day free trial, one-time purchase, Apple Silicon only.
Learn more