How many watts does a computer monitor use? Type in your wattage, the hours a day your computer monitor runs and your electricity rate, then click Calculate and you get your daily, monthly and yearly cost plus kWh consumption. Those same results also cover computer monitor power consumption.
If you have ever wondered how many watts does a computer monitor use, the short answer is that most desktop screens draw 15 to 60 watts while they are on, and well under 1 watt when they are asleep. Your own number depends on size, panel, and settings, so this guide shows you the typical ranges, a full cost example, and how to measure your own screen.
Monitor power consumption is not one fixed number. A small portable monitor may sip a few watts from a laptop, while a big gaming monitor can pull several times that at full brightness. The table below gives realistic running ranges you can use before you check the user manual for your exact model. For comparison, see how many watts does a server use.
| Monitor type | Typical screen size | Typical power draw while on |
|---|---|---|
| Portable monitor over USB-C | 13 to 16 inches | 4 to 10 W |
| Basic office display | 21 to 24 inches | 15 to 30 W |
| Mainstream LED monitor | 27 inches | 25 to 45 W |
| High-refresh gaming monitor | 27 to 32 inches | 40 to 80 W |
| Ultrawide or 4K monitor | 34 to 43 inches | 50 to 110 W |
| Old CRT monitor | 17 to 21 inches | 70 to 100 W |
So when you ask how many watts does a monitor use on a typical desk, the realistic average wattage for a modern 24 to 27 inch screen sits around 25 to 45 watts. Treat these figures as a starting estimate, because your monitor wattage changes with whatever the screen is showing.
A larger panel has more pixels to light, so screen size is the strongest single predictor of power draw. Doubling the viewing area roughly doubles the light the backlighting has to produce, which is why a 32 inch screen usually uses far more than a 22 inch one even when both are set to the same brightness.
Several design choices decide monitor power consumption before you ever touch a setting. Knowing them helps you read a spec sheet and spot a screen that will quietly inflate your electric bill.
The display technology inside the screen matters a great deal. Modern LED monitors are really LCD panels that use the same TFT layer as older models but swap in an LED light source. Older LCD screens used CCFL tubes, which are generally 20 to 30 percent less efficient. An OLED screen lights each pixel itself, so a mostly dark picture can cost very little, while a bright white page costs more. Even the panel type changes the numbers, since IPS panels often draw slightly more than VA panels at the same brightness. At the far end, a CRT or a plasma screen can use several times the power of an equal-sized LED model.
Higher resolution packs more pixels behind the same glass, and a 4K screen needs a brighter, denser backlight to look as bright as a 1080p one. That is one reason a 4K or ultrawide screen tops the table above. A mini-LED monitor adds thousands of dimming zones, which can save power on dark scenes but raises peak usage when it pushes highlights.
Built-in speakers, USB hubs, and charging ports all share the same supply, so they add to the total. A monitor that powers a laptop over USB-C can show a much higher number on the wall, because it is also charging a second device.
After the hardware, your settings are the biggest lever on monitor power use. Three of them stand out, and each one is worth testing on your own screen.
The brightness slider controls how hard the light source works, so it moves the watt reading almost in a straight line. Many screens ship with brightness set far above what a normal room needs. Dropping it from 100 percent to a comfortable 60 to 70 percent often trims 15 to 25 percent from the draw. Tune brightness by room, not by habit, and lower it again at night.
When HDR is on, the screen pushes small areas far brighter than normal. Some monitors can nearly double their draw in HDR mode, and that spike is hardest on an OLED or mini-LED panel showing bright highlights. If you only watch HDR video now and then, switch HDR on for that and leave it off for desktop work. Most operating systems let you toggle HDR per profile.
A higher refresh rate raises the screen's own consumption only slightly, often by a watt or two. The bigger effect is on your GPU. Moving the desktop from 60 Hz to 144 Hz or 240 Hz can keep the graphics card out of its low-power state, so the whole PC pulls more from the wall even though the monitor barely changed. If you do not need a fast refresh rate for work, run the desktop at 60 Hz and let games switch up on their own. Likewise, a spike in GPU load will not show up on a monitor-only reading, so measure the monitor and the PC separately.
A screen that looks off is often still drawing a trickle. Understanding standby power tells you how much that small, constant load adds up to over a year.
So, how much energy does a monitor use when it seems to be doing nothing? A modern screen that meets Energy Star rules draws roughly 0.5 to 1 watt in standby mode or sleep mode. The One Watt Initiative pushed makers below 1 watt, so a screen from 2010 may waste 5 to 10 watts while asleep. One watt running 24 hours a day for a year equals 8.76 kWh, which is small for one screen but real across a whole household.
This idle drain is often called phantom power or a vampire load. Researchers estimate it makes up 5 to 10 percent of home electricity usage. Your monitor is only one piece, alongside the TV, console, printer, and chargers. Setting the screen to sleep after five to ten minutes of inactivity is the simplest fix, and a smart power strip or unplugging a rarely used second screen removes the rest. Good sleep behavior beats manual habits because it works even when you forget.
A spec sheet gives a rated maximum, not what you actually use. To get your real monitor wattage, measure at the wall. Next, look at how many watts does a ceramic space heater use.
The most direct tool is a watt meter, also sold as a power meter. Plug it into the outlet, plug the monitor into it, and read live watts while you change the settings above. Wait a minute after each change so the reading settles.
A smart plug with energy monitoring is less precise but shows trends. A smart plug can log kWh across a week, reveal overnight standby power, and show whether a screen you think is off is still pulling current. Pair a smart plug with a power strip to group your desk. A smart plug is also the easiest way to catch a forgotten second display.
If you do not own a meter, find the manufacturer's specifications in the box or online. Labels usually list both typical usage and maximum draw, and the typical figure is closer to what you will see. Remember that a rated maximum assumes full brightness and every feature switched on.
Turning watts into money takes one formula. Multiply the power draw by the hours per day and divide by 1,000 to get a kilowatt-hour figure, then multiply by your electricity rate. An online energy usage calculator does the same thing, but doing it by hand shows what drives the result. Related: induction cooker power consumption.
$$\text{Cost} = \frac{\text{Watts} \times \text{Hours}}{1000} \times \text{Rate}$$
Take a 27 inch LED monitor that uses 41 watts at your normal settings. You use it 7.5 hours per day, six days a week, which is 312 days per year, and your energy rate is $0.17 per kWh.
| Step | Calculation | Result |
|---|---|---|
| Daily energy | 41 W × 7.5 h ÷ 1,000 | 0.3075 kWh |
| Yearly energy | 0.3075 kWh × 312 days | 95.94 kWh |
| Yearly cost | 95.94 kWh × $0.17 | $16.31 |
| Monthly cost | $16.31 ÷ 12 | $1.36 |
| Standby cost | 0.5 W for the other hours = 3.21 kWh | $0.55 |
That works out to about $1.36 per month for the active hours, plus about 55 cents a year for standby. Now compare it with a calmer setup. With brightness lowered so the screen draws 33 watts, the yearly energy falls to 77.22 kWh, so you save 18.72 kWh and about $3.18 a year. For one screen that is modest, which is the honest takeaway: a typical monitor is cheap to run, and the larger savings come from a heavy gaming rig or an office with dozens of screens.
Two people can own screens with the same diagonal and see very different monitor energy usage, because the way you use the screen matters as much as the hardware. Think about a gaming setup against a plain office desk. During gaming, the picture is brighter, the refresh rate is high, HDR is often on, and the screen rarely sits on a static white page. All of that pushes a gaming monitor toward the top of its range, often 50 to 70 watts on a 27 inch model. A typical office display shows mostly static text at moderate brightness, so it stays near its low typical usage figure of 20 to 30 watts.
The same split shows up in the hours. An office worker may keep a screen lit for eight hours a day, while a student might play for two or three, so a hungrier gaming screen does not always cost more across a year. That is why the cost per kWh in your area and your real hours matter more than the sticker wattage alone. Use the worked example above, swap in your own watts, hours, and rate, and you will have a trustworthy figure in under a minute.
A portable monitor changes the question again. Because it often runs from a laptop's battery through USB-C, the draw shows up as lost runtime rather than as a line on your power bill. A 7 watt screen on a laptop that uses 25 watts on its own cuts the runtime by roughly a fifth. If you work away from an outlet, lowering brightness and enabling a power-saving mode on the portable screen is the quickest way to stretch the battery.
For a fair measurement of two screens, read each one's watts on a static desktop, a bright full-screen video, and a dark scene, then average the three. That tells you which screen has the lower power consumption in your own use, instead of trusting a rated maximum that neither of them reaches.
Dual and triple setups multiply everything above. Two 41 watt screens at your normal brightness draw 82 watts together, which doubles the yearly figure from the worked example to about 192 kWh. Put both on one switched power strip so a single press cuts the standby load of the whole desk, and let the second screen sleep on its own whenever you are working on only one.
You do not need to give up image quality to get energy saving benefits. These steps work for any screen, and each one lowers energy consumption without touching what you see. Related: gas furnace electricity consumption.
When you shop, compare the rated and typical numbers, not just the size. Look for an Energy Star listing, an LED light source, and a low standby power figure. A smaller or lower-resolution screen is the most direct way to cut watts, and a good office display rarely needs more than 30 watts. Efficiency matters more if you run several screens all day.
Whether you are sizing a home desk or an entire office, the answer to how many watts does a computer monitor use comes down to size, panel, brightness, and how often it sleeps. Measure it once, adjust the biggest settings, and your monitor's electricity use and monitor energy usage stay low without any real sacrifice in comfort.