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

$6.38 a month

A day of use
$0.21
An hour of running
$0.03
A year
$76.53

120 W, 8 hours a day (tower only, no monitor), at Maryland’s average rate of 21.8¢ per kWh (EIA, June 2026). How we calculate this

Change the watts, hours or rate
I know the appliance's

What it costs at other usage levels

Desktop computer at 120 W and 21.8¢ per kWh
UseA dayA monthA year
1 hour a day$0.03$0.80$9.57
2 hours a day$0.05$1.59$19.13
4 hours a day$0.10$3.19$38.26
8 hours a day typical$0.21$6.38$76.53
24 hours a day$0.63$19.13$229.58
Monthly cost of a desktop computer in Maryland, nearby states and the USMaryland: $6.38; District of Columbia: $7.12; Delaware: $5.63; Pennsylvania: $6.35; Virginia: $5.03; West Virginia: $4.51; US average: $5.36Maryland$6.38District of Columbia$7.12Delaware$5.63Pennsylvania$6.35Virginia$5.03West Virginia$4.51US average$5.36

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

Maryland compared with other states

CheapestMost expensive

Maryland’s residential rate is the 14th most expensive of 51 states and DC, 3.5¢ above the US average of 18.3¢ (+19%). Maryland’s rate is up 2.6¢ from June 2025 (19.3¢, +13.2%).

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 $0.03 an hour in Maryland. A desktop computer at 120 W uses 0.120 kWh per hour, and at Maryland’s average of 21.8¢ per kWh that comes to $0.03.

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

Used 8 hours a day (tower only, no monitor), about $6.38 a month in Maryland, or $76.53 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 $0.63 a day, or $19.13 over an average month in Maryland.

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 $2.66 a month instead of $6.38, saving $3.72 in Maryland.

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

Maryland’s residential rate is the 14th most expensive of 51 states and DC, 3.5¢ above the US average of 18.3¢ (+19%). Maryland’s rate is up 2.6¢ from June 2025 (19.3¢, +13.2%). 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.