How Much Power (Watts) Does a Monitor Use?


Every computer must have a monitor in order for you to do a certain task. Although we all know approximately how much power our computer consumes and how it affects our electricity bill, we rarely pay attention to the monitor.  You may not be aware of this, but your desktop monitor is also using power.

However, many people have a habit of leaving their desktop monitor turned on for extended periods of time. In this article, we will explain what all affects the power consumption of monitors and how to accurately calculate it.

How Much Power (Watts) Does a Computer Monitor Use?

So How Much Power (Watts) Does a Monitor Use? Typically desktop monitors consume between 20 to 100 watts of power. Things that affect the power consumption of a monitor is its screen size, model, and what is emitted on it. If you use a typical 21-inch monitor for 3 hours per day, you will consume between 0.3 kWh which is around 0.01 cents per day.

The power consumption of any computer monitor varies mostly on the display technology that is used, the screen size, the build quality, brightness of the screen, what is shown on the display, and on the saving settings.

Now, let’s assume that your monitor is turned on and it consumes 40 watts per hour, 24 hours a day, 7 days a week, 365 days a year. At a cost of about 0.13 cents per kWh, the monitor increases the electricity bill by $45 every year.

If you are looking to buy a new PC monitor, this is the model we recommend, Acer SB220Q bi 21.5-Inches Full HD.

$45 per year may seem like a small figure to someone, but it’s important to remember that this is only an estimate. In some countries, the price may be more than 0.13 cents per kWh, and more powerful monitors require even more energy. Ultimately, keep in mind that this estimation can be higher or lower, in each case.

However, there can be major differences depending on the manufacturer and monitor model.

  • 22-inch monitor: approx. 20 – 45 watts
  • 24-inch monitor: approx. 20 – 60 watts
  • 27-inch monitor: approx. 50 – 100 watts
  • 30-inch monitor: approx. 100 – 150 watts

Power Consumption of Computer Monitors by Screen Size

Keep in mind that LCD & LED monitors use the same TFT (thin-film transistor) LCD technology to display images on the screen. The older LCD monitors were using the CCFL (cold cathode fluorescent) technology that mostly gives 20 to 30% less power when we compare it to LED and LCD displays.

Monitor Screen SizeLEDLCDCRTPlasma
15 inches15 W18 W65 Wn/a
17 inches18 W20 W75 Wn/a
19 inches20 W22 W80 Wn/a
20 inches24 W26 W90 Wn/a
21 inches26 W30 W100 Wn/a
22 inches30 W40 W110 Wn/a
24 inches40 W50 W120 Wn/a
30 inches50 W60 Wn/a150 W
32 inches55 W70 Wn/a160 W
37 inches60 W80 Wn/a180 W
42 inches80 W120 Wn/a220 W
50 inches100 W150 Wn/a300 W
*Keep in mind that results may vary significantly

How Much Power Does a Monitor Use in Sleep Mode?

Desktop monitors during the sleep mode use between 5 to 10 watts of power, while the laptop monitor uses about 2 watts. This is the average estimation we took according to the Energy Department. Although some monitors may consume a little more power, it’s all within normal limits, so you don’t have to worry about that. With sleep mode, you can save up to 70% of energy.

Computer Monitor TypeEnergy Consumption
Monitor in Sleep Mode0-15 Watts
Monitor Turned Off0-10 Watts

If you want to know How Much Power Does a Computer Use in Sleep Mode, read this article.

Types of Monitors And Their Power Consumption

To understand why some PC monitors of the same dimensions consume more power, while some monitors consume less power, we need to consider the materials from which they are made. Here are the 5 types of computer monitors. 

1. CRT Monitors

CRT monitor was the most commonly used monitor in the early 2000s. Also called VDU (Visual Display Unit). This monitor uses a cathode ray tube. Which is also generally called a picture tube. Most monitors have a picture tube element, and this tube is called CRT. To construct this cathode-ray tube a vacuum tube, heaters, deflection, circuits, and electron guns, and a glass screen are used. CRT monitors resemble older television sets. They are bulky, and together they also consume a lot of energy. The power consumption of CRT monitor is about 100 watts for a typical 19-inch display.

2. LCD (Liquid Crystal Display) Monitors

The LCD monitor screens use monochrome pixels. Today LCD monitors are way more popular than CRT monitors and they are very attractive. The pixels in these monitors are arranged systematically. When they are between transparent electrodes and polarizing filters. LCD monitors are of digital technology which forms a shape through a variety of crystals on a flat surface. LCD monitors provide better graphic quality and they take up less space, and it reduce the use of energy. The power consumption of an LCD monitor is about 22 watts for a typical 19-inch display.

3. LED (Light Emitting Diode) Monitors

LED monitor uses the latest technology in the market. This monitor consists of a flat panel or a slightly curved display which use light emitting diodes to run. These monitors use much less power than LCD and CRT monitors. It does not use cold cathode fluorescent (CCFL) for lighting as LCD monitors do. The great thing about LED is that they are more durable than LCD and CRT monitors. Also, LED screens do not generate much heat while running. The power consumption of LED monitors is about 20 watts for a typical 19-inch display.

4. OLED Monitor

OLED monitors have faster pixel response rates and higher contrast ratios than conventional LCD panels, but they are much more expensive. Because of this, we do not recommend them for purchase. In general, OLED technology has been on the market for quite some time, but has not gained wide popularity due to high prices. OLED technology, on the other hand, does not use LED backlighting. Instead, each pixel glows separately and functions as an independent light source. Power consumption of OLED monitors is about 21 watts for a typical 19-inch display.

5. Plasma Monitor

A Plasma panel is an array of gas-filled cells sandwiched between two parallel glass surfaces. The work of a plasma panel is based on the glow of a phosphor under the influence of ultraviolet radiation. Plasma Monitor is a modern and rather expensive device, which in a short period of time has firmly entered the life of a domestic user. The main feature of plasma is its bright and high contrast image, which is extremely pleasing to the eye. Power consumption of Plasma monitors is about 38 watts for a typical 19-inch display.

Power Consumption in Operating Modes Of Monitors

Now that we have listed what types of monitors we have, it’s time to see what operating modes are there. Depending on the mode configured on the machine, power consumption may be totally different. So let’s start:

1. “Active” Mode

In Active Mode a typical 19-inch monitor consumes about 20 Watts. The values ​​of power dissipated by the computer are determined by averaging between “full load” and the normal “on” mode of the computer (where the processor is barely functioning). LCD screens only change their power very little according to the predominant color of the displayed image.

2. Standby Mode

In Standby Mode a typical 19-inch monitor consumes between 5 to 10 Watts. When this mode is used, the computer reduces its power consumption to save energy (by  Energy Star label standards). By default, most computers enter standby mode after 20-30 minutes; which makes it possible to reduce consumption. The “standby” mode reduces the power level by cutting off the power to anything that is not useful, only the RAM and certain peripherals remaining “listening” (mouse, network card, etc.).

3. Shutdown Mode

In Shutdown Mode a typical 19-inch monitor consumes between 0 to 5 Watts. In shutdown mode, we can see that some parts of the monitor remain powered on (like led lights on some models) and continue to dissipate power. Like all electronic devices, if they are turned off, that does not mean that they do not consume any electricity.

Average Power Consumption in Operating Modes

Screen Type:Active Mode [W]Standby Mode [W]Shutdown Mode [W]
Economical 15‘’ LCD15 Watts5 Watts5 Watts
High-end 17’’ LCD25 Watts5 Watts5 Watts
17’’ economical LCD30 Watts5 Watts5 Watts
17’’ LCD35 Watts5 Watts5 Watts
** CRT 15’’40 Watts10 Watts5 Watts
CRT 17’’ economical60 Watts3 Watts3 Watts
CRT 21’’ large format115 Watts5 Watts3 Watts

Did you know that Wi-Fi Routers also consume energy? If you want to know more, read the Power Consumption of WiFi Routers article.

2 Ways To Estimate the Power Consumption of a Monitor

1. Rough Estimation of a Monitor

How much power does a monitor use? The simplest (but also the most imprecise) approach is a (rough) estimation. If you want to determine the power consumption of your desktop monitor, you basically have two options: measure or estimate.

First, let’s look at simple example.

The watt number is more or less the current power consumption. Maximum power consumption and typical power consumption can be found in good, comprehensive datasheets. How many watts the monitor consumes varies.

If you are looking for an average value, you should calculate better with the typical power consumption. If you do not want to delve deeper into the subject, you can then make an estimate for the monitor power consumption as follows:

24 ″ monitor = 25 watts

As already mentioned, the watt number describes the current power consumption. If you want to estimate the annual power consumption of the desktop monitor, the next step is to consider how many hours the monitor is in operation on average per day. You can use the following formula:

25 watts x 365 days x 3 hours = 27,375 Wh

In this example, we assumed that the monitor was used for 3 hours per day. The electricity price in the United States is currently around $0.13 per kWh. Therefore, the electricity cost for this example will be around $3,55 per year.

2. Precise Estimation By Using The Software Tool

There are also software tools that can estimate the power consumption of the PC and monitor. For Windows, for example, the Joulemeter is available directly from Microsoft. This does not measure the power consumption exactly – there are no corresponding values. However, the utilization of the hardware resources is considered and the power consumption is calculated approximately.

With a Mac you can take a look at the “System Information” tool. The power consumption is specified here in the form of mAh and mV. Divided both by 1,000 results in Ah and V. The following formula can be used to determine power consumption:

  • Ampere Hours x Volts = Watt Hours

It should be noted that the power consumption is measured in battery mode.

How to Actually Measure Power Consumption?

For me, the best and accurate way to measure power consumption of any device is by using watt meter. The purchase of a Kill A Watt Meter is not too expensive and gives the most accurate result. That’s because the power consumption is measured directly at the socket. To measure the power consumption of the monitor, you would need to use a kill a watt meter and plug it into the socket.

Table Review of Power Consumption of Monitors

Here we will list the power consumption of all popular desktop monitors on the market. Depending on the manufacturer’s information, either the maximum power consumption, the typical power consumption, or both are specified. The maximum power consumption are values that were determined when the monitor was at full brightness. The “typical power consumption”, however, was measured with reduced brightness and should come closer to the consumption under everyday conditions.

Power Consumption of 19-inch Monitors (Watts)

ManufacturerModel designationPower consumption max.Power consumption typ.
CompaqWf1909v49 W27 W
DellDell 1909W47 W25 W
EIZOS193245 W24 W.
EIZOS196140 W21 W
Samsung943BMR ivory72 W36 W
Samsung943BM70 W34 W.
Samsung943BR ivory70 W34 W.
Samsung943BR72 W34 W.

Power Consumption of 20-inch Monitors (Watts)

ManufacturerModel designationPower consumption max.Power consumption typ.
DellDell 2009WFP70 W42 W
DellDell P2010H45 W20 W
HPHP 2009v47 W.22 W
Samsung2033SN75 W37 W
SamsungF208082 W40 W
SamsungT200HD95 W50 W
SamsungT20090 W40 W

Power Consumption of 21-inch Monitors (Watts)

ManufacturerModel designationPower consumption max.Power consumption typ.
CompaqQ215945 W24 W
EIZOL99775 W33 W
EIZOS210070 W31 W
HPHP 2159m55 W27 W
HPHP 2159v45 W22 W

Power Consumption of 22-inch Monitors (Watts)

ManufacturerModel designationPower consumption max.Power consumption typ.
DellDell P221045 W22 W
EIZOS2202W51 W23 W
EIZOS2232W90 W32 W.
EIZOS2243W90 W36 W
HPHP 2229h105 W65 W
Samsung2243WM95 W47 W.
Samsung2263DX100 W52 W
Samsung2263UW95 W45 W
SamsungLD22087 W40 W
SamsungT22092 W45 W

Power Consumption of 23-inch Monitors (Watts)

ManufacturerModel designationPower consumption max.Power consumption typ.
DellDell SP2309W95 W65 W
EIZOEV2303W33 W17 W.
EIZOEV2333W45 W24 W.
HPHP 2309m56 W34 W
HPHP 2309v51 W29 W
Samsung333SW85 W45 W
Samsung2333HD95 W55 W
SamsungF2380M100 W45 W
SamsungP237080 W30 W
SamsungXL2370 LED65 W28 W

Power Consumption of 24-inch Monitors (Watts)

ManufacturerModel designationPower consumption max.Power consumption typ.
DellDell 2408WFP110 W57 W
DellDell G241042 W20 W
EIZOSX2461W110 W46 W
EIZOSX2462W95 W47 W.
Samsung245T170 W130 W
Samsung2433BW95 W50 W
SamsungP2470HD95 W52 W
SamsungP2470H85 W42 W
SamsungT240HD105 W75 W

Power Consumption of 25-inch Monitors (Watts)

ManufacturerModel designationPower consumption max.Power consumption typ.
HPHP 2509m80 W50 W

Power Consumption of 26-inch Monitors (Watts)

ManufacturerModel designationPower consumption max.Power consumption typ.
Samsung2693HM140 W110 W
SamsungT260HD105 W70 W
SamsungT26085 W55 W

Power Consumption of 27-inch Monitors (Watts)

ManufacturerModel designationPower consumption max.Power consumption typ.
DellDell 2709W160 W105 W
EIZOSX2761W115 W53 W
Samsung275T plus180 W130 W
SamsungP2770HD105 W62 W
SamsungP2770H90 W50 W

Power Consumption of 30-inch Monitors

ManufacturerModel designationPower consumption max.Power consumption typ.
DellDell 3007WFP177 W147 W
DellDell 3008WFP250 W163 W
EIZOSX3031W170 W82 W
Samsung305T plus150 W130 W

Mario

I'm the CEO and founder of Home Hacks DIY. I have been involved in home improvement since my early age. I will try to pass you my knowledge and expertise in this industry in which I have been involved for the last 10 years.

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