While Windows 10 users often close down their PCs at the end of the day, those with Macs tend to leave them on indefinitely. But is this really a good idea? We take a look at whether you should shut down your Mac every night?

Should I turn off my Mac at night?

Apple has designed macOS and Macs to be very efficient in terms of energy use and performance. With this in mind there are three options open to every user when they've finished using the computer for the day: leave it on, put it to sleep or turn it off.

If you're worried about the electricity an iMac or MacBook will use, don't be; it really is minimal when the screen is off and the Mac is put to sleep.

Laptops draw extremely little power both off and at rest. 0.21W at rest on an M1 Macbook Air will be 0.77kWh in one year if it is at rest for 10 hours every night instead of being switched off.

An iMac draws a little more power both off and at rest, but 1.36W at rest is still not very much. 10 hours of rest each night becomes 5kWh of power consumption in one year.

Of course, if you're concerned about how it uses resources, then by all means turn it off when you go to bed.

To do this, click on the Apple icon in the top left of the screen then select Shut Down from the menu.

Should I shut down my Mac every night: Shut Down

Some people argue that the cooling and reheating of components that occurs when you switch computers on and off can be damaging, but we think that Macs are built to be more robust than that.

If you're only stepping away from your Mac for a short time, then leaving it on is what we'd recommend, but overnight you'll probably want to opt for the compromise of putting it to sleep or shutting it down completely.

Is putting a Mac to sleep better than turning it off?

When put to sleep your Mac will use a reduced amount of energy and can be 'woken' a lot quicker than the time it takes to power up a Mac that's been turned off. In fact, the new Macs that feature Apple's M1 processor wake up practically instantly due to the way the system is configured, making it an even more tempting option.

A good rule of thumb is that if you're only going to be away from your Mac for an hour or two or even overnight, letting it sleep is probably the best method. Any longer than that and you'll want to power it down, for reasons outlined in the next section.

It can actually waste more energy shutting the computer down and then starting it up again, than leaving it in Sleep mode.

To put a Mac to sleep, click on the Apple icon in the top left on the screen and select Sleep from the menu.

Should I shut down my Mac every night? : Sleep

You can also schedule your Mac to sleep after a set period of inactivity, which is useful if you go to bed and forget to do it manually.

To set a Mac to automatically sleep, open System Preferences and click on Energy Saver. You'll see two options along the top of the window (Battery and Power Adapter) or just Power Adapter on iMacs and Mac minis as they don't have batteries.

You'll see a slider along the top which lets you set how long the Mac needs to be idle before the display is turned off. Choose a sensible amount, as 2 minutes will get very irksome if you're thinking about things while writing a document or presentation.

Then ensure that the Prevent computer from sleeping automatically when the display is off doesn't have its checkbox ticked.

Should I shut down my Mac every night: Auto Sleep

You'll find a few other options there to tailor your Mac's behaviour, such as putting the hard disks to sleep, and we recommend turning all of them on.

Is it bad to not shut down your Mac?

Over time, processes and apps can clog up your RAM and cause performance to drop slightly, especially on older machines. You can rectify this by closing and relaunching apps, shutting down some of those copious browser tabs you have open, or rebooting your Mac.

macOS does a good job of managing memory use, but sometimes the only way to really give your device the clean slate it needs is to shut it down and start it up once more. This will clear out the RAM and allow some processes that might have become stuck to get going once more.

There's also the point that some updates can only be applied when you reboot your Mac, so doing this every so often will ensure that everything is working as it should.

If Mac is switched off for an extended period

If you are storing your Mac for an extended period of time, Apple recommends that you don’t leave its battery fully charged (100%) or fully discharged (0%).

If stored fully charged for a long time, the battery may lose some capacity, which can shorten battery life. If stored fully discharged, the battery could fall into a deep discharge state, which renders it incapable of holding a charge.

How to schedule when your Mac goes to sleep or shuts down

Rather than relying on the display method mentioned above or your own memory, you can also set specific times when your Mac will go to sleep or shuts down and wakes back up again. This can be a useful way to mark the end of the working day, then have your machine ready to go when you arrive for the morning shift.

To do this, open System Preferences > Energy Saver then click on the Schedule button in the bottom-right corner.

Should I shut down my Mac every night: Schedule

You can now click the Start up or wake box to choose when the Mac will be ready for action (be it weekdays, weekends, every day or specific ones).

Should I shut down my Mac every night: Wake up

Beneath this you'll see another tickbox with Sleep next to it. Select this, then click on Sleep to open the other options, which are Restart and Shut Down. Now, set the time when you want to revive your Mac, and when you're happy with the schedule click OK to put this into action.

Should I shut down my Mac every night: Shut down

One thing you'll need to remember is that open applications will often prevent macOS from shutting down, as the operating system doesn't want to accidentally cause you to lose important work that might be unsaved.

To ensure the automatic shut-down works you'll need to close everything when you finish using your Mac.

If the primary reason for shutting down your Mac is to improve performance, then you might also want to consider Mac cleaning software that can automatically keep things clear of clutter and stop apps from getting greedy with your resources. We've had good experiences with Nektony's Mac Cleaner Pro and MacPaw's CleanMyMac X, but you'll find some other fine options in our roundup of the best Mac cleaner software and optimisation utilities.