Electronics & Office · West
Cost to run a desktop computer in Idaho
At Idaho’s average residential rate of 13.37¢ per kWh, a desktop computer drawing 200W for 8 hours a day, at a 70% duty cycle, costs about $4.56 per 30.44 use days. Change the numbers below to match how you actually use yours.
Desktop Computer electricity cost calculator
Use watts and running time, or enter energy from a label, meter or completed load. Your inputs stay on this device.
Enter a number within each field’s limits to calculate your cost.
Your estimated energy cost
409 kWh across 365 use days per year
Power mode includes your selected duty cycle. The monthly figure assumes 30.44 use days; the annual total uses your selected use days. These are estimates at the entered rate.
Energy charges only. Fixed utility fees, purchase, installation and maintenance are excluded. See the calculation method and sources.
Why the cost differs in Idaho
Idaho has the 5th cheapest residential electricity of the 50 US states and Washington, DC we track, at 13.37¢ per kWh against a national average of 18.16¢. That is -26.4% compared with the national figure. Idaho has some of the cheapest electricity in the country thanks to Columbia River basin hydroelectric generation, which carries almost no fuel cost once built. Retail service is regulated. Drought years that lower reservoir levels are the main risk to those rates. Winters are cold enough to create real heating demand, while dry summers keep cooling load moderate compared with the humid South.
For this appliance specifically, the difference works out to a saving of $19.58 a year against what the same desktop computer would cost at the national average rate. Run the identical appliance in Hawaii and it would cost $193 a year; in Nevada it would cost $52.00. That spread of $141 is entirely down to location.
Reducing use by 100 kWh would save $13.37 in energy charges at Idaho's average rate, compared with $18.16 at the US average. Whether a replacement appliance pays for itself also depends on its purchase price and the energy it actually saves.
Use the energy and delivery price that applies to your own utility plan in Idaho. If your plan has time-of-use prices, calculate each period separately or use a rate weighted by the electricity used in each period. Fixed monthly fees are outside this appliance energy-cost estimate.
| Location | Rate | Per month | Per year |
|---|---|---|---|
| Idaho this page | 13.37¢ | $4.56 | $54.66 |
| US average | 18.16¢ | $6.19 | $74.24 |
| Nevada cheapest state | 12.72¢ | $4.34 | $52.00 |
| Hawaii most expensive | 47.18¢ | $16.08 | $193 |
Idaho electricity rate trend
Rates in Idaho have moved from 12.50¢ to 13.37¢ per kWh between September 2025 and August 2026. The national residential average changed +3.4% from the same month a year earlier.
2025-09 to 2026-08 · cents per kWh
About running a desktop computer
A general-purpose desktop draws 100 to 200 watts; a gaming machine with a high-end GPU can exceed 600 under load. Idle draw is much lower, so actual cost depends heavily on what you do with it.
How we worked this out
The arithmetic is simple and we would rather show it than hide it. Divide watts by 1,000 to get kilowatts, multiply by hours of use and by the duty cycle to get kilowatt-hours, then multiply by your rate:
200W ÷ 1000 × 8h × 70% = 1.120 kWh/day × 13.37¢ = $0.150 per day
One honest caveat: Idaho’s figure is a state average published by the EIA. Your own utility’s tariff, any time-of-use pricing, fixed monthly service charges and local taxes all shift the real number. Put your actual per-kWh rate into the calculator above for a figure that reflects your bill.
How to estimate your desktop computer electricity use
Desktop power changes between idle, office work, gaming and other demanding tasks. The wattage printed on a computer power supply is its output capacity, not a statement that the PC constantly draws that many watts from the wall.
A power-supply capacity, CPU thermal rating or graphics-card rating is not total computer wall consumption. This tool estimates electricity only, not hardware or software cost.
- Use wall-power measurements for the workloads you actually run. A component power estimate or software reading may omit other components and power-supply losses.
- Calculate each operating period separately: average kW while working x working hours, plus average kW while idle x idle hours, plus any sleep or off-mode energy.
- For an illustrative 200W wall draw over six hours, energy use is 1.2 kWh and cost is $0.24 at $0.20/kWh. This is a scenario, not a rating for every desktop.
- Add monitors and other separately powered equipment only if they are excluded from the measurement. A power-strip measurement can already include the whole desk.
Calculation and data sources
Daily kWh = watts ÷ 1,000 × hours × duty cycle ÷ 100. Multiply kWh by your rate in dollars per kWh to get cost. The wattage, hours and duty cycle above are editable example assumptions, not EIA measurements of this appliance.
The US and state average prices come from the EIA for August 2026. A state average is a starting point; your bill is the better source for your tariff.
Questions about desktop computer running costs
How much electricity does a desktop computer use?
In this example, 200 watts at a 70% duty cycle uses 0.140 kWh per scheduled hour. At 8.00 hours per day, that is 1.120 kWh per use day. Your model and operating conditions can differ.
How much does it cost to run a desktop computer for an hour?
The default example costs $0.019 per scheduled hour at the Idaho average of 13.37¢/kWh for August 2026. This includes the selected duty cycle. Enter your watts, duty cycle and electricity price for your own estimate.
Does the annual cost assume I use it every day?
The reference tables use 365 days at the stated daily hours; monthly figures use 30.44 days. These are comparison scenarios, not forecasts. For a heater used on 90 days, enter 90 use days per year in the calculator.
Why does electricity running cost vary by state?
For August 2026, the EIA state averages range from 12.72¢/kWh in Nevada to 47.18¢/kWh in Hawaii. Equal electricity use costs more at a higher rate. Your utility tariff can differ from the state average.
Does a 750W PC power supply use 750 watts all the time?
No. Its rating describes available output capacity. Actual wall input depends on the connected components, their workload and power-supply losses. Use measured wall power for a running-cost estimate.
Should I add my monitor to the PC wattage?
Add it if the PC measurement excludes the monitor. If you measured the entire power strip, adding the monitor again would double-count it.
How can I account for gaming and idle time?
Calculate energy for each mode using its representative average input and hours, then add the kWh. One maximum wattage over all hours can overstate use.