Electronics & Office · West
Cost to run a computer monitor in Arizona
At Arizona’s average residential rate of 15.05¢ per kWh, a computer monitor drawing 35W for 8 hours a day, at a 100% duty cycle, costs about $1.28 per 30.44 use days. Change the numbers below to match how you actually use yours.
Computer Monitor 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
102 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 Arizona
Arizona has the 16th cheapest residential electricity of the 50 US states and Washington, DC we track, at 15.05¢ per kWh against a national average of 18.16¢. That is -17.1% compared with the national figure. Arizona has abundant utility-scale and rooftop solar, which suppresses midday generation costs, but the state's defining feature is extreme summer cooling demand. Phoenix-area air conditioners run near-continuously through July and August, so annual bills are high even though the per-kWh rate sits near the national average. The retail market is regulated, with most customers on Arizona Public Service or Salt River Project.
For this appliance specifically, the difference works out to a saving of $3.18 a year against what the same computer monitor would cost at the national average rate. Run the identical appliance in Hawaii and it would cost $48.22 a year; in Nevada it would cost $13.00. That spread of $35.22 is entirely down to location.
Reducing use by 100 kWh would save $15.05 in energy charges at Arizona'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 Arizona. 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 |
|---|---|---|---|
| Arizona this page | 15.05¢ | $1.28 | $15.38 |
| US average | 18.16¢ | $1.55 | $18.56 |
| Nevada cheapest state | 12.72¢ | $1.08 | $13.00 |
| Hawaii most expensive | 47.18¢ | $4.02 | $48.22 |
Arizona electricity rate trend
Rates in Arizona have moved from 15.26¢ to 15.05¢ 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 computer monitor
A typical 27-inch monitor draws 20 to 45 watts. Larger and higher-refresh displays draw more, and multi-monitor setups multiply it directly. Brightness is the single biggest variable a user controls - halving brightness meaningfully cuts draw.
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:
35W ÷ 1000 × 8h = 0.280 kWh/day × 15.05¢ = $0.042 per day
One honest caveat: Arizona’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 computer monitor electricity use
Monitor electricity use depends on the model and settings, including brightness and operating mode. A USB-C display can also supply power to a laptop or other devices, so decide which equipment your wattage includes.
This is display electricity cost. A laptop powered through the monitor should not be counted twice, and panel size alone does not establish wattage.
- Use on-mode input for your chosen settings or measure a representative period. Separate sleep or standby if not already included in a daily energy reading.
- A USB-C charging rating describes output available to a connected device, not constant extra consumption. A wall measurement of the monitor can include the power delivered to that device.
- For an illustrative steady 30W over eight hours, use is 0.24 kWh and cost is $0.048 at $0.20/kWh.
- For two monitors, add their inputs only when they operate for the same hours; otherwise calculate each schedule separately.
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 computer monitor running costs
How much electricity does a computer monitor use?
In this example, 35 watts at a 100% duty cycle uses 0.035 kWh per scheduled hour. At 8.00 hours per day, that is 0.280 kWh per use day. Your model and operating conditions can differ.
How much does it cost to run a computer monitor for an hour?
The default example costs $0.005 per scheduled hour at the Arizona average of 15.05¢/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.
How much electricity do two monitors use?
Add their measured or specified operating watts if they share the same schedule, then multiply by hours. Use separate calculations if their runtimes differ.
Does monitor wall power include USB-C laptop charging?
It can. Check the measurement boundary. If the laptop receives its power through that monitor, the monitor wall reading already includes energy supplied downstream.
Should I include sleep-mode energy?
Include it for the hours spent asleep if it is not already included in an average full-day measurement. Do not apply viewing-mode watts to every plugged-in hour.