What does a laptop cost to run?

A working day. At the US average rate of 18.34¢ per kilowatt-hour that is $23 a year.

Electronics and computing · Rated 50 W · 100% duty cycle

Running cost, US average rate

$23a year

125 kWh a year · $1.91 a month · 52 W average draw

Rated 50 W, drawing that for 100% of the 8 hours a day it is in service, 300 days a year.

50 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.

50 W
100%
8 h/day
300 days/yr
A year
$23
A month
$1.91
Electricity
125 kWh
Average draw
52 W

In the US average at 18.34¢ per kWh. Nameplate arithmetic would say 120 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 laptop that gives 120 kWh a year, or $22.

Charging draws more than running; once the battery is full the draw falls to what the machine is using.

Nameplate × hours — the usual answer120 kWh$22
What it actually draws125 kWh$23

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. 50 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. Charging draws more than running; once the battery is full the draw falls to what the machine is using.
    That gives 50 W averaged across the hours it is on.
  3. × 8 hours a day × 300 days — A working day.
    50 × 8 × 300 ÷ 1,000 = 120 kWh a year.
  4. + standby — 1 W for the other 16.0 hours a day, which is 4.8 kWh a year. People leave this out and it is not always small.
  5. × 18.34¢ — the US average residential rate for June 2026.
    125 kWh × 18.34¢ = $23 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)66 kWh$12-47%
You use it 50% more (12.00 h/day)184 kWh$34+47%
It is a smaller unit (20 W)53 kWh$9.68-58%
It is a larger unit (130 W)317 kWh$58+154%
You are in Nevada (13.11¢)125 kWh$16-29%
You are in Hawaii (52.72¢)125 kWh$66+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 use0.1 kWh1.0¢
Per day in use0.4 kWh$0.08
Per month10 kWh$1.91
Per year125 kWh$23
Over ten years1,248 kWh$229

The thing worth knowing

A laptop uses roughly a fifth of what a desktop and monitor use for the same work, because everything in it was designed to run off a battery. Over a year of full-time use the difference is real money.

What it costs in your state

The appliance is the same everywhere; the rate is not. Running this laptop costs $66 a year in Hawaii and $16 in Nevada — a difference of 4×.

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

StateRatePer yearPer month
Hawaii52.72¢$66$5.48
California34.74¢$43$3.61
Massachusetts29.61¢$37$3.08
Maine29.59¢$37$3.08
New York29.49¢$37$3.07
Rhode Island29.23¢$36$3.04
Alaska28.21¢$35$2.93
New Hampshire27.01¢$34$2.81
New Jersey24.95¢$31$2.59
Vermont24.44¢$31$2.54
District of Columbia24.39¢$30$2.54
Connecticut24.32¢$30$2.53
Michigan22.99¢$29$2.39
Maryland21.84¢$27$2.27
Pennsylvania21.73¢$27$2.26
Illinois19.89¢$25$2.07
Wisconsin19.56¢$24$2.03
Delaware19.29¢$24$2.01
Ohio19.19¢$24$2.00
Minnesota17.52¢$22$1.82
Indiana17.51¢$22$1.82
Virginia17.22¢$21$1.79
Colorado17.13¢$21$1.78
Alabama16.4¢$20$1.71
Georgia16.36¢$20$1.70
Oregon16.32¢$20$1.70
Missouri16.22¢$20$1.69
Texas15.94¢$20$1.66
Iowa15.93¢$20$1.66
Kansas15.71¢$20$1.63
South Carolina15.55¢$19$1.62
West Virginia15.45¢$19$1.61
South Dakota15.36¢$19$1.60
Wyoming15.24¢$19$1.58
Arizona15.18¢$19$1.58
Montana15.14¢$19$1.57
Florida15.1¢$19$1.57
New Mexico15.06¢$19$1.57
Washington14.91¢$19$1.55
Mississippi14.88¢$19$1.55
North Carolina14.74¢$18$1.53
Idaho14.37¢$18$1.49
Oklahoma14.33¢$18$1.49
Kentucky14.26¢$18$1.48
Arkansas14.12¢$18$1.47
North Dakota14.12¢$18$1.47
Tennessee14.07¢$18$1.46
Louisiana13.49¢$17$1.40
Utah13.37¢$17$1.39
Nebraska13.25¢$17$1.38
Nevada13.11¢$16$1.36

Questions

How much electricity does a laptop use?
About 125 kWh a year on the assumptions above — a working day. That works out to an average draw of 52 W over the hours it is in service, against a rated 50 W.
Is it expensive to run a laptop?
At the US average residential rate of 18.34¢ per kWh it costs about $23 a year, or $1.91 a month. The same appliance costs about $16 a year in Nevada and $66 in Hawaii, because the rate matters more than the appliance.
Why is your figure lower than other sites?
Because 50 W is what the appliance draws while it is actually drawing, not the average over the time it is switched on. Charging draws more than running; once the battery is full the draw falls to what the machine is using. Multiplying the rating by the hours gives 120 kWh a year, which is 1× the real figure.
What is the cheapest way to run a laptop?
Leaving it plugged in at 100% is fine for the bill; the charger tapers to near nothing. It is battery longevity, not electricity, that argues against it.

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