Should I Turn Off My Computer at Night?

It’s the age old question: Should I turn off my computer at night, or leave it on?

We’ve always been told that it’s “bad for the electronics” to keep turning a computer off and on, and it’s better for the life of the computer just to leave it on all the time. I am here to set the record straight: Turning off your computer is not damaging.

The theory behind this myth is this: turning on a computer ran electricity through all the components and they heated up and expanded. Then turning it off cooled down the components and they contracted. Expand, contract, expand, contract– over time that is damaging to the computer. It’s simply not true. How many people do you know that leave their TV’s on all day to “protect the electronics”? No one. And modern TV’s have most of the same components that a computer has.

Here is some more good news about powering off your computer regularly: It will save you money.

An average company of ten spends over $2600 every year to power computers no one is using.

Consider a company of 10 employees, working normal business hours, all using Dell Optiplex 3010 computers. These are the computers we are currently recommending to our clients. Over the course of an average year, most computers are only in normal use about 37% of the time.

At current electricity rates, this company would be paying $2655.30 every year just to power computers that no one is using! Compare that to the company who has their employees put their computers into sleep or standby mode when they leave for the day: $63.73 for the year. That is enough savings to pay for new computers for the whole company every 3 years, which is about how often they should be replaced anyway. From just turning off computers at night, this company can have free computers for life.

Click here to show the math


  1. Dell Optiplex 3010 computers use about 250 watts while in normal operation, and about 6 watts while in standby mode.
  2. Most people want their computers powered up on weekdays from 8:00 am to 6:00 pm for 48 weeks per year (accounting for holidays, sick days, and vacation).
  3. There are 8760 hours in a year, 2400 of which are business hours, 6360 non-business hours
  4. Calculations are made at the current rate of $0.167 per kilowatt-hour
  5. The equation for calculating the cost of electrical usage is: ((watts * hours) / 1000 ) * rate

Normal Operation:  ((250 watts * 6360 non-business hours) / 1000 ) * $0.167 per kilowatt-hour = $265.53 per computer per year to power the computer when not in use. Multiplied by 10 computers in the company = $2655.30 per year.

Sleep Mode: ((6 watts * 6360 non-business hours) / 1000 ) * $0.167 per kilowatt-hour = $6.37 computer per year to leave the computer in sleep mode when not in use. Multiplied by 10 computers in the company = $63.70 per year.

Savings: $265.53 – $6.37 = $259.16 per computer per year in savings by putting the computer to sleep. Multiplied by 3 years = $777.48 savings per computer over the recommended lifespan of a computer. A new Dell Optiplex 3010 with Microsoft Office and no monitor right now is $819.


Similarly, most families using the same computer can save over $200 per year by putting it into standby when no one is at home.

Unfortunately, not everyone can turn their computers off when they leave. Some people do work from home and need to remotely access their computers. Some computers do a lot of calculation work during non-business hours. IT providers often do regular maintenance to computers during these off-hours. However, much of the IT work can be scheduled and condensed to the weekend, and most people don’t need to access their computers from home. Even accounting for the ones that do, your company can find significant financial saving, as well as reduced environmental impact, merely by putting computers to sleep when they are not needed.