What does a computer monitor cost to run?

One 27-inch display through a working day. At the US average rate of 18.34¢ per kilowatt-hour that is $11 a year.

Electronics and computing · Rated 30 W · 100% duty cycle

Running cost, US average rate

$11a year

62 kWh a year · $0.95 a month · 31 W average draw

Rated 30 W, drawing that for 100% of the 8 hours a day it is in service, 250 days a year.

30 W while running never cycles — the plate is right for once

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.

Residential average for June 2026, from the EIA. Your own tariff may differ; you can read it off your bill.

30 W
100%
8 h/day
250 days/yr
A year
$11
A month
$0.95
Electricity
62 kWh
Average draw
31 W

In the US average at 18.34¢ per kWh. Nameplate arithmetic would say 60 kWh too high.

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 computer monitor that gives 60 kWh a year, or $11.

Backlight draw is steady for a given brightness. Size and brightness account for nearly all the range.

Nameplate × hours — the usual answer60 kWh$11
What it actually draws62 kWh$11

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. 30 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. Backlight draw is steady for a given brightness. Size and brightness account for nearly all the range.
    That gives 30 W averaged across the hours it is on.
  3. × 8 hours a day × 250 days — One 27-inch display through a working day.
    30 × 8 × 250 ÷ 1,000 = 60 kWh a year.
  4. + standby — 0.5 W for the other 16.0 hours a day, which is 2 kWh a year. People leave this out and it is not always small.
  5. × 18.34¢ — the US average residential rate for June 2026.
    62 kWh × 18.34¢ = $11 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.

If…ElectricityA yearvs default
You use it half as much (4.00 h/day)33 kWh$5.96-48%
You use it 50% more (12.00 h/day)92 kWh$17+48%
It is a smaller unit (12 W)26 kWh$4.77-58%
It is a larger unit (90 W)182 kWh$33+194%
You are in Nevada (13.11¢)62 kWh$8.13-29%
You are in Hawaii (52.72¢)62 kWh$33+187%

What it costs per hour, day and month

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

PeriodElectricityCost
Per hour in use0 kWh0.6¢
Per day in use0.2 kWh$0.05
Per month5.2 kWh$0.95
Per year62 kWh$11
Over ten years620 kWh$114

The thing worth knowing

Brightness is the whole variable. Most monitors ship at or near maximum, which is calibrated for a shop floor rather than an office, and halving it typically cuts draw by a third with no practical loss. Two large displays left on overnight cost more per year than the computer driving them.

What it costs in your state

The appliance is the same everywhere; the rate is not. Running this computer monitor costs $33 a year in Hawaii and $8.13 in Nevada — a difference of 4×.

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

StateRatePer yearPer month
Hawaii52.72¢$33$2.72
California34.74¢$22$1.79
Massachusetts29.61¢$18$1.53
Maine29.59¢$18$1.53
New York29.49¢$18$1.52
Rhode Island29.23¢$18$1.51
Alaska28.21¢$17$1.46
New Hampshire27.01¢$17$1.40
New Jersey24.95¢$15$1.29
Vermont24.44¢$15$1.26
District of Columbia24.39¢$15$1.26
Connecticut24.32¢$15$1.26
Michigan22.99¢$14$1.19
Maryland21.84¢$14$1.13
Pennsylvania21.73¢$13$1.12
Illinois19.89¢$12$1.03
Wisconsin19.56¢$12$1.01
Delaware19.29¢$12$1.00
Ohio19.19¢$12$0.99
Minnesota17.52¢$11$0.91
Indiana17.51¢$11$0.90
Virginia17.22¢$11$0.89
Colorado17.13¢$11$0.89
Alabama16.4¢$10$0.85
Georgia16.36¢$10$0.85
Oregon16.32¢$10$0.84
Missouri16.22¢$10$0.84
Texas15.94¢$9.88$0.82
Iowa15.93¢$9.88$0.82
Kansas15.71¢$9.74$0.81
South Carolina15.55¢$9.64$0.80
West Virginia15.45¢$9.58$0.80
South Dakota15.36¢$9.52$0.79
Wyoming15.24¢$9.45$0.79
Arizona15.18¢$9.41$0.78
Montana15.14¢$9.39$0.78
Florida15.1¢$9.36$0.78
New Mexico15.06¢$9.34$0.78
Washington14.91¢$9.24$0.77
Mississippi14.88¢$9.23$0.77
North Carolina14.74¢$9.14$0.76
Idaho14.37¢$8.91$0.74
Oklahoma14.33¢$8.88$0.74
Kentucky14.26¢$8.84$0.74
Arkansas14.12¢$8.75$0.73
North Dakota14.12¢$8.75$0.73
Tennessee14.07¢$8.72$0.73
Louisiana13.49¢$8.36$0.70
Utah13.37¢$8.29$0.69
Nebraska13.25¢$8.22$0.68
Nevada13.11¢$8.13$0.68

Questions

How much electricity does a computer monitor use?
About 62 kWh a year on the assumptions above — one 27-inch display through a working day. That works out to an average draw of 31 W over the hours it is in service, against a rated 30 W.
Is it expensive to run a computer monitor?
At the US average residential rate of 18.34¢ per kWh it costs about $11 a year, or $0.95 a month. The same appliance costs about $8.13 a year in Nevada and $33 in Hawaii, because the rate matters more than the appliance.
Why is your figure lower than other sites?
Because 30 W is what the appliance draws while it is actually drawing, not the average over the time it is switched on. Backlight draw is steady for a given brightness. Size and brightness account for nearly all the range. Multiplying the rating by the hours gives 60 kWh a year, which is 1× the real figure.
What is the cheapest way to run a computer monitor?
Turn the brightness down to what the room actually needs, and set the display to sleep after five minutes rather than running a screensaver, which draws full power to show you a picture nobody is watching.

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