How many watts is a pc monitor: Everything Explained Here

If you are wondering how many watts is a pc monitor, a typical modern desktop monitor uses approximately 10–40 watts while operating, although large 4K displays, high-refresh gaming screens, and OLED monitors can consume considerably more. Small portable displays may use fewer than 10 watts, while some large gaming monitors draw 60 watts or more during demanding viewing conditions. Your actual consumption depends on the exact model, screen brightness, displayed content, connected devices, and operating mode. Understanding these factors helps you estimate your electricity bill, choose an efficient display, and avoid confusing a monitor’s maximum power rating with its everyday energy consumption.

How many watts is a PC monitor?

For a typical desktop setup, 20–30 watts is a useful starting estimate for an ordinary LCD monitor. A smaller office display may use less, while a large, bright, high-refresh-rate gaming monitor may draw substantially more. There is no single wattage that applies to every PC monitor.

The following ranges are practical estimates for preliminary calculations, not guaranteed specifications or measured averages for every model.

These categories overlap because screen size alone does not determine electricity consumption. A well-designed 27-inch office monitor can draw less power than a brighter 24-inch gaming monitor operating at demanding settings.

Manufacturer specifications illustrate this variation. LG lists 14.5 watts for the on-mode consumption of its 27-inch 27BA550-B office monitor. Its 31.5-inch 32BR50C-B display is rated at 25 watts in on mode. At a higher performance tier, LG lists typical power consumption of 55 watts for its 32-inch 32BQ85U-W 4K monitor. These figures come from individual manufacturer specifications, not a universal test comparing all monitor categories.

The most useful rule is to check the official specification sheet for your exact model and then measure its actual consumption if you need a reliable electricity-cost estimate.

Typical monitor wattage by size and display technology

Screen dimensions and panel technology help establish a reasonable starting point, but their effects overlap. Comparing displays with similar features is more useful than assuming every monitor of the same size uses identical power.

Small portable and office monitors

Portable USB-C monitors commonly use just a few watts because they have relatively small panels and modest power requirements. ENERGY STAR records include portable displays with reported on-mode figures around 3–7 watts, although specific models and testing conditions differ.

Traditional 22–24-inch office monitors often operate in the single-digit to low-tens watt range. For example, ENERGY STAR’s Most Efficient display listings include a 23.8-inch EIZO FlexScan FLT with reported on-mode consumption of 4.25 watts. Another listed 23.8-inch Philips monitor reports 8.74 watts.

Those are examples of selected efficient products, not representative figures for every office display. Brightness, integrated features, and the manufacturer’s measurement method still matter.

Larger LCD and 4K monitors

A 27-inch LCD monitor generally requires more power than a smaller screen when brightness and other features are comparable. However, a newer, efficient 27-inch office model can remain below 20 watts.

For larger 31.5–32-inch displays, consumption can increase because the panel has a greater viewing area and may include a stronger backlight, higher brightness, speakers, or additional electronics. The LG 32BR50C-B specification provides a concrete reference at 25 watts in on mode.

Resolution does not produce a simple, predictable increase in wattage. A 4K monitor has more pixels than a Full HD monitor of the same dimensions, but that does not mean it automatically consumes four times as much electricity. Backlight efficiency, panel design, brightness, and internal processing influence the final result.

Gaming monitors and high-refresh-rate screens

Gaming displays may need more power because of their backlights, high refresh rates, HDR capabilities, and additional features. However, a refresh rate of 240 Hz does not mean a monitor necessarily consumes twice the power of a 120 Hz model.

Look at the exact monitor specifications rather than multiplying wattage according to refresh rate. Some gaming displays remain relatively efficient, while premium models with high brightness, complex electronics, or additional connectivity can consume considerably more.

OLED monitors require a separate consideration. Their power usage can change significantly depending on the content shown and the selected brightness. A dark game scene and a predominantly white desktop can produce different readings on the same OLED display.

In a TechSpot review, the Alienware AW3423DW 34-inch QD-OLED monitor generally consumed around 40–60 watts during typical tested use. That result illustrates one product under particular conditions; it should not be treated as a universal figure for all OLED monitors.

What affects how many watts a monitor uses?

Several factors explain why two monitors with similar screen dimensions can have different power requirements.

Screen brightness

Brightness is one of the most important settings you can control. On LCD monitors, increasing brightness generally requires the backlight to produce more light, which increases power consumption.

Reducing brightness to a comfortable level can lower electricity use without requiring a smaller monitor or a less capable display. However, the exact savings depend on the panel and its brightness-control system.

A monitor set near maximum brightness in a sunlit room may draw more power than the same model used at a moderate setting in a dimmer room.

Resolution and refresh rate

Resolution describes the number of pixels displayed on screen. Refresh rate describes how frequently the display can update its image.

Both can influence power use, but neither provides a direct wattage calculation. Higher refresh rates may require additional processing and electronics activity, while high-resolution displays may incorporate different panel and backlight designs.

For example, choosing 144 Hz instead of 60 Hz should not automatically be interpreted as a fixed percentage increase in electricity consumption. The two models may have entirely different power characteristics even if their resolutions are identical.

HDR and picture settings

High Dynamic Range (HDR) can allow a display to produce brighter highlights and more demanding visual output. Depending on the implementation, enabling HDR or selecting a high-brightness picture mode may increase consumption.

OLED displays are particularly sensitive to the image being shown. Brightness and the proportion of illuminated pixels can affect their power requirements. LCD displays respond differently because they rely on a backlight.

If energy consumption matters, measure the monitor under your normal workload rather than relying on a single reading taken with a blank screen.

Speakers, USB ports, and connected devices

Some monitors include integrated speakers, webcams, USB hubs, Ethernet ports, or USB-C laptop charging. These features can increase overall power draw when active.

A USB-C monitor that supplies power to a laptop may consume substantially more electricity at the wall than the display alone would require. In that situation, the monitor is also delivering power to another device.

When comparing specifications, check whether the reported figure covers the display in normal operation or includes power delivered through connected-device features.

Ambient light and automatic brightness

Some monitors adjust brightness based on their surroundings or use energy-saving modes to reduce consumption. These functions may lower power use when full brightness is unnecessary.

Ambient lighting also affects how much brightness you need for comfortable viewing. A monitor in a bright room may need a higher setting than one in a controlled office environment.

The goal is not to make the screen uncomfortably dim. Choose an appropriate brightness for the room and allow the display to reduce consumption whenever practical.

How many watts is a PC monitor in sleep mode?

A monitor generally consumes much less electricity in sleep mode than while displaying an image. Many modern displays specify sleep consumption below 0.5 watts, although the exact figure varies by model and connected features.

LG’s specifications for the 27BA550-B, for example, list sleep-mode consumption below 0.5 watts and power consumption below 0.3 watts when switched off. These are manufacturer ratings for that particular monitor, not guaranteed values for every display.

A monitor in sleep mode is not necessarily using zero electricity. It may retain circuitry for detecting input signals, responding to controls, or waking when the computer resumes operation.

Leaving an efficient monitor asleep overnight usually has a small electricity cost. Nevertheless, enabling automatic display sleep prevents unnecessary operation and is useful when a screen remains unused for long periods.

Be careful when comparing standby specifications. Some manufacturers report a separate off-mode figure, while others specify sleep-mode consumption or use different test conditions. The figures are not automatically interchangeable.

Monitor power rating versus actual electricity consumption

A specification sheet or power adapter label can reveal useful information, but it is essential to understand what the number represents.

A monitor may have a power adapter rated for 60 watts without consuming 60 watts continuously. The adapter rating indicates its power-delivery capability under specified conditions, not the amount of energy the monitor always uses.

For example, an adapter marked 19 volts and 3.42 amps has a nominal output rating of approximately 65 watts:

19 V × 3.42 A = 64.98 W

This calculation estimates the adapter’s rated output. It does not establish the monitor’s actual consumption during ordinary viewing.

Look for specification terms such as these:

• On-mode power: Consumption while the display is operating under the relevant test conditions.

• Typical power consumption: A manufacturer-defined representative figure, where provided.

• Maximum power consumption: A higher specified operating limit or maximum under stated conditions.

• Sleep-mode power: Consumption when the display enters its low-power state.

• Power-off consumption: Consumption when switched off but still connected to electricity.

Maximum consumption is useful when assessing electrical capacity, but typical on-mode consumption is generally more appropriate for estimating an electricity bill.

Also distinguish the monitor’s own consumption from the combined consumption of a complete PC. A graphics card, processor, motherboard, and other desktop components require additional electricity. A monitor’s wattage does not represent the entire computer’s power draw.

How much electricity does a PC monitor use per month?

Watts describe the rate at which a device consumes power. Your utility bill is based on energy, usually measured in kilowatt-hours (kWh).

To estimate consumption, divide the monitor’s wattage by 1,000 to convert watts into kilowatts, then multiply by the number of hours it operates.

The formula is:

Energy used (kWh) = Power (W) ÷ 1,000 × Operating hours

For a daily estimate, multiply by hours per day. For an annual estimate, multiply by hours per day and days per year.

Calculate the electricity cost

To estimate the cost, multiply the energy used in kWh by your electricity rate.

Electricity cost = Energy used (kWh) × Rate per kWh

The U.S. Energy Information Administration reported an average U.S. residential electricity price of 17.30 cents per kWh for 2025. Actual rates vary substantially by state, utility, and electricity plan, so the following calculations use $0.173 per kWh as an illustrative reference rather than a guaranteed current rate for every household.

Assume each monitor operates for eight hours per day, every day of the year.

These calculations assume constant power while operating, eight hours of use every day, and no additional standby consumption. Actual costs can differ because monitor wattage changes with settings and activity.

Consider a 25-watt monitor used eight hours daily. It consumes approximately 73 kWh per year, costing around $12.63 at the example rate. That is roughly $1.05 per month.

An 80-watt monitor under the same schedule consumes 233.6 kWh per year, costing approximately $40.41. Its operating cost is higher, but neither figure includes the desktop computer or other connected equipment.

What if you leave the monitor on all day?

Operating hours can matter more than small differences between monitor models.

A 25-watt monitor running continuously for 24 hours per day would use:

0.025 kW × 24 hours × 365 days = 219 kWh per year.

At $0.173 per kWh, that amounts to approximately $37.89 annually, excluding standby behavior and changes in actual consumption.

This is why power management is worthwhile even when the screen itself does not seem particularly energy-hungry. A modest reduction in wattage helps, but avoiding unnecessary operating hours can also deliver meaningful savings.

How much does a dual-monitor setup cost?

For two monitors, calculate each display separately and add the results.

For example, assume one monitor consumes 25 watts and a second consumes 40 watts. Both operate eight hours daily throughout the year.

Their combined power draw is 65 watts, and their annual energy use is:

0.065 kW × 8 hours × 365 days = 189.8 kWh.

At $0.173 per kWh, the estimated annual cost is approximately $32.84.

This estimate covers only the displays. The desktop’s additional consumption is separate, and the two monitors may not draw the same amount of power even if they have identical advertised specifications.

How to measure your monitor’s actual wattage

If the specification sheet does not provide a useful typical value, direct measurement is the most reliable way to learn how much electricity your monitor uses in your setup.

A plug-in electricity meter that reports watts and cumulative kWh can measure a monitor’s AC power consumption. Choose a meter rated for your electrical system and the load being measured.

Follow these steps:

• Plug the electricity meter into the wall outlet or an appropriately rated power strip.

• Connect the monitor’s power supply to the meter.

• Turn on the monitor and use your normal brightness, resolution, and refresh-rate settings.

• Allow the display to stabilize, then record its instantaneous wattage.

• Repeat the measurement with representative activities, such as office work, a bright webpage, gaming, or HDR content.

• Check the meter’s accumulated kWh after a typical work session to determine actual energy use.

For a USB-C monitor charging a laptop, the measured wall power may include energy delivered to the laptop. Disconnect the laptop or disable charging when you want to isolate the monitor’s display-related consumption.

To estimate typical usage, take several readings under conditions that resemble your real workload. A single maximum reading may exaggerate everyday use, while a reading taken on a dark screen may underestimate consumption for bright applications.

If you only need an approximate answer, you do not need to buy additional hardware. The manufacturer’s on-mode rating is a reasonable starting point, and the calculation above turns that figure into an estimated electricity cost.

Ways to reduce monitor electricity consumption

You can reduce your monitor’s energy use without necessarily replacing it. Begin with settings and habits that have little impact on the experience of using your PC.

• Lower brightness to a comfortable level. Avoid maximum brightness in a dim room, particularly when using an LCD display.

• Enable automatic display sleep. Configure Windows or your operating system to turn off the screen after a reasonable period of inactivity.

• Turn the display off when you finish working. This is especially worthwhile when you will be away for several hours.

• Use energy-saving settings where appropriate. Some monitor features reduce power while maintaining a usable picture.

• Disable unnecessary powered accessories. USB charging, integrated lighting, and other features can add to the monitor’s overall consumption.

• Compare actual efficiency before upgrading. A new monitor may use less power, but purchasing an expensive replacement solely to save a few dollars annually is unlikely to make financial sense for many users.

Microsoft Windows supports configurable screen and sleep timeouts, while the U.S. Department of Energy recommends using display power management features and turning displays off when they are not needed.

A screen saver is not the same as an energy-saving mode. An animated screen saver can keep a display active, and it should not be relied on to reduce electricity consumption.

OLED owners should also understand that dark themes can reduce display power under suitable viewing conditions because darker images generally require less emitted light. The exact savings depend on the panel, brightness settings, and displayed content. Avoid assuming that a dark theme will produce a fixed percentage reduction across all displays.

Finally, compare efficiency figures alongside the characteristics you care about. A monitor that consumes 10 fewer watts might be useful for an always-on workspace, but resolution, viewing comfort, color accuracy, refresh rate, and connectivity can matter more when selecting a replacement.

Frequently asked questions

Does a monitor use 100 watts of power?

Some monitors can approach or exceed 100 watts in demanding conditions, particularly large displays or models with high brightness and additional powered features. However, 100 watts is not a typical operating figure for many ordinary office monitors. Check the exact model’s on-mode and maximum power specifications before assuming that it uses this much electricity.

Does a 144 Hz monitor use more electricity than a 60 Hz monitor?

It can, but the difference depends on the specific displays and settings. A higher refresh rate may increase power consumption, but screen brightness, panel design, size, and additional features also matter. Comparing two monitors’ actual power specifications is more reliable than assuming refresh rate alone determines wattage.

Does a monitor consume electricity when the PC is off?

Yes, it may continue drawing a small amount of power if it remains connected to electricity and enters standby or another low-power state. The result depends on the monitor’s design and configuration. To minimize consumption completely, use the manufacturer’s supported shutdown procedure and disconnect power when appropriate.

Is a monitor’s wattage included in the PC’s PSU wattage?

No. A desktop power supply primarily powers components inside the computer, such as the motherboard, CPU, drives, and graphics card. A standard externally powered monitor uses its own power source. USB-powered peripherals and monitors with laptop-charging functions require separate consideration when estimating total electricity consumption.

Which monitor size uses the least electricity?

Smaller monitors generally have lower power requirements when other characteristics are comparable. However, an efficient 27-inch monitor may draw less power than a less-efficient smaller display. Look at manufacturer consumption specifications rather than selecting a screen based on dimensions alone.

Final verdict

For everyday planning, estimate around 20–30 watts for a typical office monitor, then adjust according to its size, panel technology, brightness, and features. Larger gaming and OLED monitors may consume considerably more, while efficient office displays can use less than 15 watts.

The most accurate approach is to check the exact model’s on-mode power rating and measure it under your normal conditions when precision matters. Multiply the measured wattage by your actual operating hours to estimate kWh, then apply your local electricity rate. In many desktop setups, the monitor’s annual electricity cost is modest, making sensible brightness settings and automatic sleep more practical first steps than replacing a working display solely to save power.