Is it better to leave the computer on or turn it off?

Updated: 09/15/2017 by Computer Hope

Power buttonEven though sessions vary with usage, all of us need to step away from our computers at some point. Many of our users wonder if it's a good idea to leave their computers on, or turn them off. The answer to this question depends on a number of factors ranging from electricity bills to concerns about wear and tear. The following sections address the "on or off" debate from many viewpoints, allowing the viewer to make a decision for him or herself.

Power concerns

Associated costs

One of the biggest contributing factors when deciding whether or not you turn off your machine is the cost of leaving it on. A bill for electricity can be expensive and a computer—like many household electronic devices—is a contributing factor. Unless you'll be away for a very long time from a computer that is on, the difference in price isn't a large concern. However, if you're looking to save a few dollars a month, shut it down.

Note: If you decide to leave your computer on all day, we recommend turning off the monitor if you're leaving for more than half of an hour.

Time to resume

In our opinion, the time for your computer to resume working is a bigger factor the cost of electricity. For instance, if you open and close your laptop frequently, you don't want to have to reboot it completely each time. Knowing a bit about the different power states of a computer should help you in your decision.

  • Sleep - All of the open applications and files are stored in RAM, and the rest of the computer components are put into a low-power state. This option is best when you're only going to be stepping away from your computer for a short time because it boots back to the desktop the fastest.
  • Hibernate - With hibernate mode, all of the open applications and files are copied onto your computer's boot drive, and the rest of the computer is essentially shut down. This option is good if you'll be away from your computer for a medium period of time.
  • Shut down - When you shut a computer down, all files and applications are closed, and power to the computer's internal components is cut off. Shutting down is a good option if you'll be away from you computer for an extended period of time (e.g., more than eight hours).

Note: The time to resume from different power states is much more significant on hard disk drives than it is on solid-state drives. Since boot times on modern SSDs are so fast, shutting down your computer is not nearly as much of a factor.

Leaving your computer on over night

Our recommendation for most users is turn off your computer when you go to bed as it will save you a bit of money on your electricity bill. However, if you want tasks to run during the night such as a backup, ScanDisk, Defrag, or a virus scan, you'll need to leave your computer on while you sleep.

Will turning off a computer wear down moving parts (e.g., fans)?

No. The only moving parts that caused an issue internally were within a component, not the computer itself. In older hard drives, the head would come into contact with the disk platter upon shutdown, which caused it to wear. However, any hard drive manufactured today doesn't have this issue.

Does turning off a computer wear down the power button?

Before 1994, it may have been beneficial to leave the computer on due to potential power switch related issues associated with certain manufacturers that caused the power buttons to break prematurely. However, this issue was only applicable to a very small portion of old OEM computers, and today, is no longer a problem. Power buttons can still wear out, but they have a life cycle that will far outlast the other components of your computer.

Does turning off a computer cause soldering cracks?

No. Solder is meant to withstand changes in temperature; turning a computer off frequently will not harm it. For example, many individuals turn their TV on and off each day, sometimes several times. Much like a computer, components within the TV get hot and cool down, and these devices have no issues.

Will turning my computer off help prevent a power surge?

Power surgeNo. A power surge destroys electrical devices regardless of whether they are on or off. Having the power cord connected to a surge protector can safeguard a computer from an electrical surge.

Note: If a storm causes a blackout or brownout, it can cause problems with a desktop computer. To prevent these power-related problems from affecting a computer use a UPS.

Computer power misconceptions

"As the computer boots, it takes more power.

This statement is not true.

"Turing off my computer causes power surges."

This statement is also untrue.

"Leaving a computer on causes it to overheat."

Unless a fan within a computer fails while it is on, the computer will not overheat.

"A laptop is different than a desktop it should be turned off."

Although physically different, a laptop can also remain on 24/7 just like a desktop, and all of the information mentioned above still applies. The exception here, of course, is if you are running a laptop off of the battery (not plugged in). In this case, the laptop is not going to be able to run all day, and you should conserve your battery usage.