How Much Does It Cost to Run a Computer per Day and Month?

Source: Planning watts of 150 and 6 hours a day, hours of use a day, for a desktop with a monitor. Price: 17.23 cents per kWh, the 2025 US residential average from EIA Form EIA-861.

The monthly cost is 3% of the $150.68 average US electric bill. It runs all year, so the yearly cost is twelve times the monthly figure.

One figure cannot fit every home. These three cases show how much the answer moves with the equipment and the hours.

The lowest case costs $2 a month and the highest $10. Use the calculator above to match your own.

The same computer costs different amounts depending on the state, because the price per kWh differs. Here are the three cheapest states, the US average and the three costliest, for the same 27 kWh a month.

Source: U.S. Energy Information Administration, Form EIA-861 (final 2025 data). Price is residential revenue divided by sales and includes fixed charges.

See electricity rates in every state to find your own.

A computer draws far less at the desktop than under load. A laptop uses a small fraction of what a gaming desktop does, and a monitor adds its own draw. A machine left on all day uses more energy than one that runs for six hours at higher power.

The kind of computer matters most, then the hours it is on. Laptops draw tens of watts, ordinary desktops draw about 100 to 200 watts with a monitor, and high-end machines draw more under load. Sleep settings decide how much a machine uses when you are not at it.

The range for this kind of appliance runs from about 30 to 400 watts. At 6 hours a day that is $1 to $13 a month, which is why checking the label on yours is worth the minute.

• Set the computer to sleep after a short idle time, and let the monitor turn off sooner.
• Switch off a desktop and its power strip at night if you will not use it.
• Choose a laptop or a small desktop when you do not need a powerful graphics card.

Next step: Gaming PC costs. For general ideas, read how to lower your electric bill.

Other appliances in the electronics and lighting group: LED Light Bulb, Television, Gaming PC, Crypto Miner, Hair Dryer.

The cost is watts divided by 1,000, times hours, times your price per kWh. The 150 watts is a planning figure for this kind of appliance, set from typical product ratings, and the 6 hours is an assumed day of use. Neither is copied from a federal table. Federal guidance describes the method and warns that real wattage varies, so we publish our own typical ranges and label them as such. Prices come from EIA Form EIA-861 for 2025.

The calculation is the standard one used in the U.S. Department of Energy's consumer guidance on estimating appliance energy use. Wattage varies by product age and features, so the label on your own appliance beats any average. Read more in our methodology.