Electronics & Office · West
Cost to run a computer monitor in California
At California’s average residential rate of 33.25¢ per kWh, a computer monitor drawing 35W for 8 hours a day costs about $2.83 a month. Change the numbers below to match how you actually use yours.
Quick answer
Based on 35W and 33.25¢/kWh, the California average for May 2026.
Calculate your own cost
Everything is worked out in your browser. Your numbers are never sent to our server.
— per year
Why the cost differs in California
California has the 50th cheapest residential electricity of the 51 US states and territories we track, at 33.25¢ per kWh against a national average of 18.44¢. That is +80.3% compared with the national figure. California is the country's second-most expensive state, and the reasons are mostly on the delivery side rather than the generation side: wildfire hardening, transmission undergrounding and renewable procurement mandates all recover through rates. Critically, time-of-use pricing is near-universal here, so when you run an appliance matters as much as how long. Coastal cooling demand is mild; inland valleys are not.
For this appliance specifically, the difference works out to an extra $15.14 a year over what the same computer monitor would cost at the national average rate. Run the identical appliance in Hawaii and it would cost $53.14 a year; in Idaho it would cost $12.62. That spread of $40.52 is entirely down to location.
That works out to roughly 1.0% of a typical California household's annual electricity bill - modest individually, though appliances in this range add up.
Because California is among the most expensive states for electricity, efficiency upgrades pay back faster here than almost anywhere. A more efficient computer monitor that saves a given number of kilowatt-hours saves noticeably more money in California than the same upgrade would in a cheap-power state.
Time-of-use pricing is near-universal in California, so when you run this appliance can matter as much as how long. Peak-period rates can be several times the off-peak price, and the state average sits somewhere in between.
| Location | Rate | Per month | Per year |
|---|---|---|---|
| California this page | 33.25¢ | $2.83 | $33.98 |
| US average | 18.44¢ | $1.57 | $18.85 |
| Idaho cheapest state | 12.35¢ | $1.05 | $12.62 |
| Hawaii most expensive | 52.00¢ | $4.43 | $53.14 |
California electricity rate trend
Rates in California have moved from 33.59¢ to 33.25¢ per kWh over the last twelve months of published data. Nationally, residential rates rose about 6.2% year over year.
2025-06 to 2026-05 · 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.
What actually changes the cost
- Models vary widely, from about 20W to 80W. Check the nameplate on your own unit rather than assuming an average, because the spread is more than 2x.
- If your utility offers time-of-use pricing, shifting this load off-peak can cut its cost substantially without using any less energy.
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 × 33.25¢ = $0.093 per day
One honest caveat: California’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.
Questions about computer monitor running costs
How many watts does a computer monitor use?
A typical computer monitor draws about 35 watts while running, with most models falling between 20W and 80W. Check the nameplate label or manual for your specific unit - the range is wide enough that averages can mislead.
How much electricity does a computer monitor use per day?
At around 8 hours of use a day and a 100% duty cycle, that works out to roughly 0.28 kWh per day, or about 8 kWh a month. Your actual figure depends on your usage and model.
Why does the cost differ so much between states?
Residential electricity rates across the US range from about 12.35 cents per kWh in North Dakota to 46.62 cents in Hawaii - nearly a fourfold difference. The same computer monitor, used identically, therefore costs almost four times as much to run in the most expensive state as in the cheapest.
Is it cheaper to run a computer monitor at night?
Only if you are on a time-of-use or variable tariff. On a flat rate, the time of day makes no difference to cost. If you are on time-of-use pricing, off-peak hours are typically materially cheaper, and shifting this load can reduce its cost without reducing usage.