An average desktop computer uses between 60 and 300 watts. It is very difficult to know exactly how much computers use on average because there are so many different hardware configurations. The computer power supply is not an accurate way to measure energy use because the power supply output is advertised as the max amount of watts a power supply can output. The electricity usage of a computer also heavily depends on the video card, a high end video card can use a lot of power and having more than one (SLI or Crossfire mode) during heavy gaming or 3d rendering can use a large amount of energy. We estimate that an average modern desktop PC will use approximately 100 watts of power, not including the display screen.
See the energy consumption of a desktop computer using 100 Watts for 6 hours a day @ £0.19 per kWh.
Cost Per Hour: £0.0190
Cost Per Day: £0.1140
Cost Per Month: £3.47
Cost Per Year: £41.61
kWh Per Day: 0.60
Tip: To save energy turn off your computer when it is not being used or enable power saving features such as hibernate, standby or sleep mode. Power saving modes will allow you to turn on a computer quickly when you need to use it. Sleep mode typically uses only 1-5 watts of power and can be set to turn on automatically after a set time of inactivity.
If you want to find out the exact amount of electricity your desktop computer is using we recommend you buy an electricity usage monitor or a power meter, which sits between your power socket and any devices you plug in. This will allow you to accurately find out the exact amount of energy your computer is using.