How much does a computer monitor cost to run?

Updated 7 November 2026 · ClearCost UK · 3 min read

A computer monitor uses about 30W. At 27p per kWh, running it 6 hours a day costs about £0.008 an hour, £1.48 a month and £18 a year.
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Computer monitor running cost at different electricity prices

The figures use 30 watts and 6 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 30W computer monitor, one hour uses 0.03 kWh.

Computer monitor: 30W, 6 hours a day

Electricity pricePer hourPer dayPer monthPer year
20p per kWh£0.006£0.04£1.10£13
25p per kWh£0.007£0.04£1.37£16
30p per kWh£0.009£0.05£1.64£20
35p per kWh£0.011£0.06£1.92£23

Typical wattage. Check the label on your own appliance.

Computer monitor 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 30W computer monitor for different amounts of time each day at 27p per kWh.

Computer monitor at 27p per kWh

Hours per dayCost per dayCost per monthCost per year
30 minutes£0.004£0.12£1
1 hour£0.008£0.25£3
2 hours£0.016£0.49£6
4 hours£0.032£0.99£12
8 hours£0.065£1.97£24
24 hours£0.194£5.92£71
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How much power does a computer monitor use?

A typical computer monitor is rated around 30W, which is 0.03 kW. Over a year of the use above that adds up to about 66 kWh. Large or high-refresh monitors can use 50W or more.

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

ApplianceTypical powerCost per hourCost per year
Computer monitor (this page)30W£0.008£18
Electric blanket100W£0.027£59
Electric fireplace1,400W£0.378£552
Smart speaker3W£0.001£7
Electric car home charger7,000W£1.89£897
Immersion heater3,000W£0.810£591
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Ways to cut the cost of running a computer monitor

  • 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 computer monitor?
About £0.008 an hour, £1.48 a month or £18 a year at 27p per kWh, using it 6 hours a day.
How much does a computer monitor cost to run for 24 hours?
Running a 30W computer monitor for 24 hours straight would use 0.72 kWh and cost about £0.19 at 27p per kWh.
How many watts does a computer monitor use?
A typical computer monitor uses about 30 watts. The exact figure is on the label or in the manual.
What electricity price should I use?
The Ofgem price cap sets the maximum unit rate for most standard variable tariffs and changes every three months. Use the p/kWh figure on your own bill.

Results are estimates for information only, not financial advice. Read the full disclaimer.

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