How much does a desktop computer cost to run?
Desktop computer running cost at different electricity prices
The figures use 200 watts and 5 hours a day. Your own price per kWh is on your electricity bill, so pick the row closest to it, or change the numbers in the calculator.
Cost = watts ÷ 1,000 × hours × price per kWh. For a 200W desktop computer, one hour uses 0.2 kWh.
Desktop computer: 200W, 5 hours a day
| Electricity price | Per hour | Per day | Per month | Per year |
|---|---|---|---|---|
| 20p per kWh | £0.040 | £0.20 | £6.09 | £73 |
| 25p per kWh | £0.050 | £0.25 | £7.61 | £91 |
| 30p per kWh | £0.060 | £0.30 | £9.13 | £110 |
| 35p per kWh | £0.070 | £0.35 | £10.65 | £128 |
Typical wattage. Check the label on your own appliance.
Desktop computer running cost by hours of use
How long you use it matters more than almost anything else. The table shows the cost of using a 200W desktop computer for different amounts of time each day at 27p per kWh.
Desktop computer at 27p per kWh
| Hours per day | Cost per day | Cost per month | Cost per year |
|---|---|---|---|
| 30 minutes | £0.027 | £0.82 | £10 |
| 1 hour | £0.054 | £1.64 | £20 |
| 2 hours | £0.108 | £3.29 | £39 |
| 4 hours | £0.216 | £6.57 | £79 |
| 8 hours | £0.432 | £13.15 | £158 |
| 24 hours | £1.30 | £39.45 | £473 |
How much power does a desktop computer use?
A typical desktop computer is rated around 200W, which is 0.2 kW. Over a year of the use above that adds up to about 365 kWh. A desktop with a strong graphics card can pull 400W or more under load but only 50W when idle.
Wattage varies between models. Look for the power rating on the label, in the manual or on the maker's website, and enter it in the calculator for an exact answer.
How it compares with other appliances
Typical wattage and typical use for each appliance, at the same electricity price. A high cost per hour does not always mean a high yearly cost, because it depends on how often you use it.
Compared at 27p per kWh
| Appliance | Typical power | Cost per hour | Cost per year |
|---|---|---|---|
| Desktop computer (this page) | 200W | £0.054 | £99 |
| LED TV (55 inch) | 90W | £0.024 | £44 |
| Games console | 200W | £0.054 | £59 |
| Laptop | 50W | £0.014 | £30 |
| Wi-Fi router | 10W | £0.003 | £24 |
| Phone charger | 10W | £0.003 | £3 |
Ways to cut the cost of running a desktop computer
- Use it less at peak times if you are on a time-of-use tariff, and more when power is cheapest.
- Choose a model with a high energy rating when you replace it. The saving over its life is often bigger than the price difference.
- Switch it off at the wall when it is not in use if it has a standby draw.
- Check your tariff. A lower unit rate cuts the cost of every appliance in the house.
Sources and further reading
Questions people ask
How much does it cost to run a desktop computer?
How much does a desktop computer cost to run for 24 hours?
How many watts does a desktop computer use?
What electricity price should I use?
Results are estimates for information only, not financial advice. Read the full disclaimer.