When it comes to turning off your computer, myths and legends abound. Some will tell you that turning off your computer is bad for the computer, that your computer only has so many ons and offs in it and that by turning it off every time you stop using it, you'll eventually kill your machine. The other great myth about computers is that it takes more energy to turn your computer on than it does to maintain it in sleep mode.

Does Turning Your Computer Off and On Hurt It?

According to the United States Department of Energy, there are no computers on the market that actually last long enough for the negative effects of turning your computer off and on to affect anything.

From EERE:

Most PCs reach the end of their "useful" life due to advances in technology long before the effects of being switched on and off multiple times have a negative impact on their service life. The less time a PC is on, the longer it will "last." PCs also produce heat, so turning them off reduces building cooling loads.

As you can see, the more time a computer spends turned off, the longer it will last.

Does Turning on Your Computer Use More Energy than Leaving it On

No. It's a silly myth. Jaymi Heimbuch debunked this myth in an earlier post:

..our technology has advanced so much that lights, appliances and gadgets can be turned off any time they aren't needed and turned back on when they are, without any risk of harming them. And doing so means energy savings.

So go ahead and turn off your computer if it makes sense to.