How much does a desktop computer cost to run?
A desktop computer typically draws around 250 W while running. Ratings vary widely between models, so check the label and change the figure below.
per kWh
W
g CO2 per kWh
Cost per year
206.04
- Cost per month
- 17.17
- Cost per day
- 0.56
- Cost per hour of use
- 0.07
- Energy per year
- 735.8 kWh
- Energy per day
- 2.0160 kWh
- Carbon dioxide per year
- 184.0
- Annual cost of standby alone
- 1.64
Show the working
- Power = 250
- Hours per day = 8
- Days per year in use = 365
- Electricity price = 0.28
- Standby power = 1
- Grid carbon intensity = 250
- kw = 250 / 1000 = 0.25
- daily_kwh = 0.25 * 8 = 2
- standby_kwh = 1 / 1000 * (24 - 8) = 0.016
- Energy per day = 2 + 0.016 = 2.016
- Energy per year = 2.016 * 365 = 735.84
- Cost per day = 2.016 * 0.28 = 0.564 48
- Cost per year = 735.84 * 0.28 = 206.035
- Cost per month = 206.035 / 12 = 17.1696
- Cost per hour of use = 0.25 * 0.28 = 0.07
- Carbon dioxide per year = 735.84 * 250 / 1000 = 183.96
- Annual cost of standby alone = 0.016 * 365 * 0.28 = 1.6352
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
Scenarios & local history
Compare a saved scenario
Recent calculations
The formula
- daily energy = power in kW x hours
- annual cost = daily energy x days x price per kWh
Nameplate wattage is the maximum draw, not the average. A cycling appliance like a fridge or a freezer averages far less.
Standby draw is small per device and adds up across a house: ten devices at 2 W each is 175 kWh a year.
Running cost of a desktop computer at different tariffs
| Price per kWh | Per hour | Per year at 8 h/day |
|---|---|---|
| 0.10 | 0.0250 | 73.00 |
| 0.15 | 0.0375 | 109.50 |
| 0.20 | 0.0500 | 146.00 |
| 0.25 | 0.0625 | 182.50 |
| 0.30 | 0.0750 | 219.00 |
| 0.40 | 0.1000 | 292.00 |
Frequently asked
How many watts does a desktop computer use?
Typically around 250 W while running, though models vary. Check the rating plate.
How much electricity does it use per day?
About 2.00 kWh at 8 hours of use.
Related calculators
- Electricity cost
- Appliance comparison
- Home energy audit
- Running cost of a dishwasher
- Running cost of a games console
- Running cost of a hair dryer
- Running cost of a hot tub
- Running cost of a laptop
- Running cost of a microwave
- Running cost of a pool pump
- Running cost of a refrigerator
- Running cost of a television
- All energy & environment calculators →