Cost to run a desktop computer
What an office desktop costs
At 17 cents a kilowatt hour, an office desktop costs 3.4 cents an hour while it is drawing power. 6 hours a day with 60 percent average draw is 0.72 kWh a day, $3.67 a month and $44.68 a year. Change any of those three numbers in the calculator and the answer moves with them, because there is nothing else in the sum.
The label figure is 200 watts. That is what the device draws while it is working, not what it draws around the clock.
| Hours of use a day | Energy a day | Cost a month | Cost a year |
|---|---|---|---|
| 1 h | 0.12 kWh | $0.61 | $7.45 |
| 2 h | 0.24 kWh | $1.22 | $14.89 |
| 4 h | 0.48 kWh | $2.45 | $29.78 |
| 6 h | 0.72 kWh | $3.67 | $44.68 |
| 8 h | 0.96 kWh | $4.90 | $59.57 |
What changes the number
- A desktop at light load sits between 60 and 120 W, and jumps to 200 W under sustained work. Machines with a separate graphics card sit at the top of that range even when idle.
- Sleep is not off. A sleeping machine still draws 2 to 6 W, which is small, but a machine left on for a year at idle is not small at all.
- A laptop doing the same work draws 30 to 60 W. If the desktop exists for one task, the laptop is the cheaper machine to run.
Find your own wattage
A plug-in meter is the quickest read. Otherwise, the power supply rating divided by three is a reasonable guess for an office machine.
What this does not include
It does not count monitors, docks or network equipment, which can add another 50 W to a workstation.
Check it against your own numbers
The [running cost calculator](../index.html?device=desktop-pc) opens with this device already selected and its wattage filled in. Replace the wattage with your own reading, set the hours you actually use, and the monthly and yearly figures update in place.
Related: [A 1,500 W space heater](../space-heater/index.html), [An electric blanket](../electric-blanket/index.html), [A dehumidifier](../dehumidifier/index.html).