What does a desktop computer cost to run?

Run the numbers on your own use

Change any of these and the figures update. The defaults are the typical case described above; your rate is the input that moves the answer most.

Why this is lower than the number you will see elsewhere

Almost every published answer to this question multiplies the rating on the label by the hours the appliance is switched on. For a desktop computer that gives 200 kWh a year, or $37.

Office workloads sit close to idle most of the time.

The arithmetic, step by step

Nothing here is hidden, so you can check it or change it. Working in the order the formula runs:

1. 100 W — what it draws while it is actually drawing. This is the rating on the plate.
2. × 100% — the share of its in-service time it is really pulling that. Office workloads sit close to idle most of the time.
   That gives 100 W averaged across the hours it is on.
3. × 8 hours a day × 250 days — A working day, five days a week.
   100 × 8 × 250 ÷ 1,000 = 200 kWh a year.
4. + standby — 2 W for the other 16.0 hours a day, which is 8 kWh a year. People leave this out and it is not always small.
5. × 18.34¢ — the US average residential rate for June 2026.
   208 kWh × 18.34¢ = $38 a year.

Change any assumption in the calculator above and every figure on this page moves with it. The two that matter most are your rate, which varies 4× across the country, and the hours — the duty cycle is a property of the appliance, but the hours are a property of you.

How sensitive is that number?

A single figure invites more confidence than it deserves. Here is the same appliance under assumptions either side of the default, so you can see how much of the answer is the appliance and how much is the guess about how you use it.

Everything else held at the default. The spread here is the honest error bar on the headline figure.

What it costs per hour, day and month

At 18.34¢ per kWh, the US residential average for June 2026.

The thing worth knowing

Sleep draws a couple of watts; a screensaver draws the full amount plus the monitor. Screensavers stopped saving anything when CRTs went away.

Against laptop

Sleep after 15 minutes, and let the monitor blank after five. In numbers: a desktop computer costs $38 a year on these assumptions, and laptop doing a comparable job costs $23 — a difference of $15 a year, or $153 over ten years at today’s rate.

Both at 18.34¢/kWh, each on its own standard usage assumption. Ten years is roughly the service life of either.

What it costs in your state

The appliance is the same everywhere; the rate is not. Running this desktop computer costs $110 a year in Hawaii and $27 in Nevada — a difference of 4×.

Cost of running one desktop computer for a year, by state. Residential average price, EIA June 2026.

Other electronics and computing costs

• Gaming PC

  $111 a year

  Four hours of gaming a day on a mid-to-high-end build.

• UPS battery backup

  $40 a year

  A mid-size unit protecting a computer or a network rack.

• Games console

  $39 a year

  Three hours of play a day.

• OLED television

  $38 a year

  A 65-inch OLED, five hours a day, mixed content.

• LED television

  $31 a year

  A 55-inch 4K set, five hours a day, out-of-the-box brightness.

• AV receiver

  $30 a year

  A 7.2-channel receiver at normal listening levels.

Questions

Source: U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A, June 2026. U.S. Government work, public domain.

How every figure on this page is computed · Where the data comes from