How much does a desktop computer cost to run?

A 200-watt unit running 8 hours a day costs about $9.04 a month at 18.83¢ per kWh. Change the inputs for your equipment and local rate.

Updated July 16, 2026EIA residential rate data

Calculate your cost

Start with a representative input, then edit all three numbers.

18.83¢/kWh U.S. average
W
hr
¢/kWh
$9.04/ month
$0.30/ day
$109.97/ year

This setup uses about 48 kWh in a 30-day month.

Runtime comparison
ScheduleHours/dayCost/month
Half runtime4$4.52
Starting point8$9.04
Longer runtime12$13.56

Same 200-watt input and 18.83¢/kWh rate; only runtime changes.

The quick formula

0.2 kW × 8 hours × $0.1883 = $0.30 per day

Convert watts to kilowatts, multiply by the active hours used each day, then multiply by the electricity price in dollars per kWh. Multiply the daily result by 30 for the monthly estimate shown above.

How to read this estimate

A general-purpose desktop usually spends much of the day below its peak power draw. Workload, monitor use, and idle behavior determine whether an eight-hour workday is inexpensive or surprisingly wasteful.

The starting values keep this page useful before you have a label or meter reading. They do not describe every model, climate, operating mode, or household.

What changes the cost?

  1. 01

    Processor workload, graphics hardware, and connected storage

  2. 02

    Number, size, and brightness of monitors

  3. 03

    Active hours, idle time, sleep settings, and power-supply efficiency

Ways to spend less

  • Enable automatic display-off and system sleep.
  • Disconnect unused external drives and accessories.
  • Measure at the wall if the machine runs intensive tasks for long periods.

Rate source U.S. Energy Information Administration, Electricity Retail Sales

EIA calculates average retail revenue per kilowatt-hour from reported residential sales and revenue. It is a statewide monthly average, not a quoted utility tariff, and an individual bill may also include fixed fees, tiers, taxes, riders, or time-of-use pricing.

Source period 2026-04 · retrieved July 16, 2026.