MonitorsComputer Monitor

LG 27BP55U Monitor Manual

Setup, everyday use, maintenance and troubleshooting for the 27 in. 4K IPS-type monitor, with verified specifications.

  • Screen27 in.
  • Resolution4K UHD
  • On-mode power22.4 W
  • Est. yearly cost$11.86

About the LG 27BP55U

The LG 27BP55U is a 27 in. 4K IPS-type monitor certified under the ENERGY STAR program for displays. Its native resolution is 3840 × 2160 pixels (4K UHD), about 163 pixels per inch.

It uses an IPS LCD panel with a rated maximum luminance of 336 cd/m² (nits). Listed signal and data interfaces include HDMI, DisplayPort, and USB. A USB-C port with Power Delivery can charge a connected laptop at up to 96 W while carrying video and data.

Measured on-mode power is 22.4 W, with 0.19 W in sleep and a total energy consumption (TEC) rating of 69.8 kWh per year — 12% below the ENERGY STAR limit for a display of this size and resolution. That TEC rating is lower than 23% of the 1,472 Computer Monitor models in our database.

Specifications

LG 27BP55U specifications
BrandLG
Model number27BP55U
Display typeComputer Monitor
Screen size (diagonal)27.0 in.
Screen area310 sq. in.
Panel technologyIPS LCD
Native resolution3840 × 2160
Resolution class4K UHD
Pixel density163 ppi
Maximum luminance336 cd/m²
Enhanced Performance DisplayNo
Signal and data interfacesHDMI, DisplayPort, USB
USB-C with Power DeliveryYes
Maximum USB-C charging power96 W
Power sourceExternal AC adapter
On-mode power22.4 W
Sleep-mode power0.19 W
Off-mode power0.16 W
Total energy consumption (TEC)69.8 kWh/yr
ENERGY STAR TEC limit79.6 kWh/yr
Below ENERGY STAR limit12%
ENERGY STAR Most EfficientNo

Safety information

  • Place the monitor on a stable, level surface. When using a monitor arm or wall mount, choose one rated for the monitor's weight and VESA pattern and tighten it as instructed.
  • Use only the external power adapter supplied with the display (or an identical replacement). An adapter with a different voltage or polarity can damage the monitor.
  • Keep the ventilation openings clear and do not place the display near radiators, heaters or in direct sunlight.
  • Do not expose the display to rain, moisture or spilled liquids. If liquid gets inside, unplug it immediately and have it checked before further use.
  • Unplug the display during lightning storms or when it will be unused for an extended period.
  • Keep fingers clear of the hinge and height-adjustment mechanism when tilting, pivoting or raising the screen.

Setup

Position the 27 in. screen about 20–30 in. (50–75 cm) from your eyes, directly in front of you, with the top line of text at or slightly below eye level. Tilt it back 10–20° and place it at a right angle to windows to minimize glare.

  1. Assemble the stand

    Attach the stand or monitor arm while the display is lying face-down on the protective packaging or a soft cloth. Do not press on the screen.

  2. Connect the video cable

    USB-C is the simplest option with a laptop: one cable carries video, USB data and up to 96 W charging power. If your laptop's own charger is rated higher than 96 W, it may charge slowly under heavy load — keep its adapter handy. DisplayPort is generally the best choice for high refresh rates from a desktop graphics card. HDMI works with most laptops, desktops and game consoles.

  3. Set resolution and scaling

    In your operating system's display settings, select the native resolution of 3840 × 2160. At about 163 pixels per inch, a scaling setting around 150% usually gives comfortably sized text; adjust to taste.

  4. Adjust brightness

    Set brightness so a white page looks similar to a sheet of paper under your room lighting — typically 100–150 cd/m² for office work, well below this model's 336 cd/m² maximum. Lower brightness reduces both eye strain and power use.

Using your monitor

Picture modes and color

Use the on-screen display (OSD) menu to choose a picture preset. A standard or sRGB mode is best for office work and web browsing. Avoid "dynamic" contrast modes for photo editing, as they shift brightness with screen content.

Power management

The monitor enters sleep automatically when the computer stops sending a signal, dropping to 0.19 W. Set your computer to turn off the display after 5–15 minutes of inactivity so this happens during breaks. With the power button off, the monitor draws 0.16 W.

USB-C charging and docking

With a USB-C laptop connected, the monitor supplies up to 96 W through the same cable that carries the picture. Many monitors keep the USB-C port powered in sleep so the laptop continues to charge; check the OSD for a "USB charging in standby" option if you want to disable it.

Features

USB-C Power Delivery
Single-cable video, data and laptop charging (up to 96 W).

Care and maintenance

WhenWhat to do
WeeklyDust the screen with a dry microfiber cloth using light pressure.
When smudgedPower the display off, then wipe with a microfiber cloth lightly dampened with water. Never spray liquid directly on the screen or use ammonia- or alcohol-based glass cleaners on anti-glare coatings.
Every 3 monthsVacuum or brush dust from the ventilation slots and check that cables are fully seated and not pulling on the ports.
Every 6 monthsCheck the manufacturer's support site for firmware updates, especially if you see compatibility issues with new computers or docks.

Troubleshooting

Most display problems trace back to cables, input selection or computer settings. Work through these checks before contacting support; for model-specific messages, consult the manufacturer's manual.

ProblemPossible causeWhat to try
"No signal" messageWrong input selected; loose cable; computer asleep or outputting to another screen.Select the correct input in the OSD, reseat both cable ends, wake the computer, and press Win+P (Windows) or check Displays settings (macOS).
Text looks blurry or the picture does not fill the screenComputer not sending the native resolution; scaling or overscan settings.Set the resolution to 3840 × 2160 and adjust OS scaling instead; turn off overscan or "aspect" options in the OSD.
Flicker, dropouts or black screen at high refresh ratesCable not rated for the bandwidth; adapter or dock limitation.Use a certified DisplayPort or Ultra/Premium High Speed HDMI cable, connect directly without adapters, or lower the refresh rate to test.
Colors look washed out over HDMILimited RGB range sent by the computer or console.Set the output to full RGB range in the graphics driver, or match the monitor's HDMI range setting.
Monitor does not wake from sleepDeep-sleep option on the input; graphics driver issue.Press a monitor button or reselect the input; disable deep sleep / auto-input in the OSD; update the graphics driver.
Laptop not charging over USB-CLaptop needs more power than the port supplies; cable not rated for charging; USB-C port on laptop is data-only.Check that the laptop accepts USB-C charging and needs no more than 96 W; use the supplied or a 5 A certified cable; try another USB-C port on the laptop.

Energy use and running costs

The LG 27BP55U has a total energy consumption (TEC) rating of 69.8 kWh per year. ENERGY STAR's TEC method assumes the screen is on about 35% of the time (roughly 8.4 hours a day) and asleep the rest. At $0.17 per kWh, it costs about $11.86 per year.

Estimated from 22.4 W on and 0.19 W sleep at $0.17/kWh, 365 days a year.
Daily useEnergy per yearCost per year
4 hours on, 20 asleep34.1 kWh$5.80
8 hours on, 16 asleep66.5 kWh$11.31
12 hours on, 12 asleep99 kWh$16.83

On-mode power is measured at the factory-default brightness. Turning brightness up or charging a laptop through USB-C increases consumption; using short sleep timers reduces it.

Frequently asked questions

What size and resolution is the LG 27BP55U?

It has a 27 in. screen with a native resolution of 3840 × 2160 (4K UHD), giving a pixel density of about 163 ppi.

How much power does the LG 27BP55U use?

It draws 22.4 W when on and 0.19 W in sleep. Its ENERGY STAR TEC rating is about 69.8 kWh a year, or $11.86 at $0.17/kWh.

Can the LG 27BP55U charge a laptop over USB-C?

Yes. It has a USB-C port with Power Delivery rated at up to 96 W, so a compatible laptop can charge, send video and use the monitor's USB ports over one cable.

What inputs does the LG 27BP55U have?

The ENERGY STAR record lists HDMI, DisplayPort, and USB. Port counts and versions (for example HDMI 2.1 or DisplayPort 1.4) are not included in the certification data; check the manufacturer's specifications.

What panel type does the LG 27BP55U use?

It uses an IPS LCD panel with a rated maximum luminance of 336 cd/m². IPS-type panels offer wide viewing angles and consistent color.

Sources and disclaimer

Specifications on this page come from the ENERGY STAR certified monitors dataset published by the U.S. Environmental Protection Agency (record certified August 16, 2022), retrieved October 7, 2026.

The setup, operating, maintenance and troubleshooting guidance is written by ManualHarbor's editors for this specific product type and configuration. It is an independent guide — not a reproduction of the manufacturer's manual — and ManualHarbor is not affiliated with LG. Always follow the safety instructions, installation requirements and warranty terms supplied with your unit, and contact LG or an authorized service provider for warranty repairs and replacement parts.

Running-cost figures use assumed U.S. average utility prices and are estimates for comparison only. See our editorial methodology for details.