How Many Watts Does a Computer Monitor Use?

There are many factors, including model, size, and setup, that affect how many watts a computer monitor uses, but the average device consumes around 84 watts.

I’ve owned, fixed, and worked with many different monitors in my life. That hands-on experience, backed up by additional research and my personal knowledge of computers, allowed me to put together the following article.

Each section in this guide looks at computer monitor wattage. It does that by analyzing the factors that impact energy usage, the ways to measure such usage, and the best methods to reduce it.

Key Takeaways

  • Monitor wattage isn’t a constant. It differs greatly based on many key traits, such as monitor size, emitter, brand, and accessories.
  • Your monitor being in active, standby, sleep, or shutdown mode drastically affects the amount of energy it uses.
  • Cutting back on extra power draw, switching up your hardware, and streamlining your monitor are all ways to cut back on your device’s energy consumption.

Monitor Energy By Size and Type

Monitors are not incredibly energy-intensive devices. Even so, they do need electricity to run. While the amount of watts used differs from model to model, most machines consume around 84 on average. That then shifts depending on factors like size, brand, and emitter.

Of those, size is one of the most important. Without taking in other factors, a 22-inch monitor uses between 20 and 45 watts, a 24-inch uses 20 to 60 watts, a 27-inch uses 50 to 100 watts, and a 30-inch uses 100 to 150 watts. The larger a monitor, the more energy it needs to run.

Type matters too. There are several different kinds of monitor’s on the market, and they all consume energy in different ways.

Cathode ray tube (CRT) monitors are extremely large devices that have a ton of weight. While they’re outdated, they’re good to bring up for reference. The behemoths consumed about 100 watts for a 19-inch display.

In contrast, liquid crystal display (LCD) monitors, which utilize transparent electrodes and polarizing filters to function, only consume 22 watts for a 19-inch display.

For 19-inch LED monitors that number drops 20 watts, and goes up again to 38 watts for plasma machines. In both cases, the monitors use very little energy when compared to other popular electronic devices.

Different Monitor Modes

Another factor to pay attention to is the mode your monitor is in. The machines consume different amounts of energy at different times based on their personal settings. 

When a monitor is in active mode, meaning that it’s on and operating, it consumes the maximum amount of energy. In contrast, when it’s in standby mode, power consumption drops quite a bit.

That number then goes down to just 5 to 10 watts of consumption in sleep mode and 0 to 5 watts when shutdown. That’s a huge drop off and a great way to save energy in the long run.

In fact, Windows users can take advantage of such modes by going to the “power and sleep” tab in settings and choosing how often they want their computer to go to sleep. You can also put in when you want the monitor to turn off when it’s not in use. 

How to Reduce, and Determine, Energy Consumption

Different monitors use different amounts of energy. Regardless of what type you own, it’s good to reduce that output whenever possible. That’s better for the environment and saves you money in the long run.

The first, and easiest way, to cut down on your monitor’s usage is to make sure your GPU doesn’t use any excess power. As graphics cards eat so much energy, if left unchecked high end GPUS can use a lot of watts 

It’s also critical to reduce unnecessary power draw when your computer’s not in use. Always remember that external devices utilize their own power supply and will up the wattage even when they aren’t actively working.

Though it’s much more drastic, you can also charge or upgrade your machine’s hardware. That’s not always an easy fix, and it’s quite expensive, but it will make your monitor much more efficient in the long run.

Something else you want to keep in mind, and a good tip when figuring out your monitor’s usage, is to actually calculate the exact wattage. That’s not something you can do easily. Even so, it can be done with outside help.

You can estimate using the above information, or you can get a much more accurate figure by downloading a third party software tool like Joulemeter or purchasing a kilowatt meter. Those tools do a great job in helping you know how and when you’re reducing power consumption.


In this section I cover some of the most common questions asked about computer monitor watt usage.

Do LCDs or LEDs consume less power?

On the whole, LEDs use less energy than their LCD counterparts. In fact, the models consume the least amount of power out of any monitor type due to the fact that they block light as opposed to emitting it.

How Many Watts Does a 32-Inch Monitor Use?

There’s no one set amount that a certain size monitor will use. Every model differs depending on external factors. That being said, smaller monitors do tend to use less power than larger ones. A 32-inch will consume less energy than a 40 inch or 50 inch.

Do Older Monitors Use More Power?

On the whole, yes. Older models are not as energy efficient as most modern ones, which then causes them to eat up more power in order to run at peak or premium performance.

Final Words

Computer monitors don’t have a ton of wattage, but the energy consumption differs between models quite a bit. Always research how much yours takes in, note its unique traits, and use that to make a decision about what type you want.

How many watts does your computer monitor use? Did that play a factor in you getting it? Let us know in the comments below!

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