How much does a desktop computer cost to run in Washington?

$4.35 a month

A day of use
$0.14
An hour of running
$0.02
A year
$52.24

120 W, 8 hours a day (tower only, no monitor), at Washington’s average rate of 14.9¢ per kWh (EIA, June 2026). How we calculate this

Change the watts, hours or rate
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What it costs at other usage levels

Desktop computer at 120 W and 14.9¢ per kWh
UseA dayA monthA year
1 hour a day$0.02$0.54$6.53
2 hours a day$0.04$1.09$13.06
4 hours a day$0.07$2.18$26.12
8 hours a day typical$0.14$4.35$52.24
24 hours a day$0.43$13.06$156.73
Monthly cost of a desktop computer in Washington, nearby states and the USWashington: $4.35; Idaho: $4.20; Oregon: $4.77; US average: $5.36Washington$4.35Idaho$4.20Oregon$4.77US average$5.36

A typical model draws about 120 W (Virginia Cooperative Extension).

Washington compared with other states

CheapestMost expensive

Washington’s residential rate is the 13th cheapest of 51 states and DC, 3.4¢ below the US average of 18.3¢ (−19%). Washington’s rate is up 2.0¢ from June 2025 (13.0¢, +15.0%).

A cheaper way to do the same job

Ways to spend less

  • Set it to sleep after 15 minutes idle.
  • Shut it down at night instead of leaving it on.
  • For email and browsing, a laptop does the same job on much less power.

Questions

How much does it cost to run a desktop computer per hour?

About $0.02 an hour in Washington. A desktop computer at 120 W uses 0.120 kWh per hour, and at Washington’s average of 14.9¢ per kWh that comes to $0.02.

How much does a desktop computer add to your electric bill?

Used 8 hours a day (tower only, no monitor), about $4.35 a month in Washington, or $52.24 a year.

How much does it cost to run a desktop computer 24 hours a day?

Running nonstop, a desktop computer would use 2.88 kWh a day and cost $0.43 a day, or $13.06 over an average month in Washington.

How many watts does a desktop computer use?

A typical model draws about 120 W (Virginia Cooperative Extension). Check the label on yours: cost scales directly with watts, so a 20% lower wattage means a 20% lower bill.

Is it cheaper to run a desktop computer or a laptop?

Using a laptop for the same hours instead would cost about $1.81 a month instead of $4.35, saving $2.54 in Washington.

Why does a desktop computer cost more or less to run in Washington than elsewhere?

Washington’s residential rate is the 13th cheapest of 51 states and DC, 3.4¢ below the US average of 18.3¢ (−19%). Washington’s rate is up 2.0¢ from June 2025 (13.0¢, +15.0%). The appliance uses the same energy everywhere; only the price per kWh changes.

Sources

Usage assumptions (hours a day, season) are ours and listed on the methodology page. Found an error? Tell us.