How to choose the pixel pitch of an LED display

Terms such as "P2.5", "P4" and "P6" in LED display proposals define the display's pixel pitch. Choosing the right pixel pitch is the technical decision that most affects both image quality and the project budget.

What is pixel pitch?

Pixel pitch is the distance between the centers of two adjacent LED pixels and is measured in millimeters. P4 means there is 4 mm between pixels. The smaller the pitch, the more pixels fit on the same surface; the image looks sharper at close range, and the cost rises accordingly.

Choosing by viewing distance

The closest comfortable viewing distance in meters equals the pixel pitch value in millimeters (e.g. 4 meters for a P4 display); as viewing distance gets shorter, smaller pixel pitches should be chosen for a clean image.

This table should be treated as a starting point in the selection process. The type of content (text or video), the size of the display and the budget can change the final decision. Choosing an unnecessarily small pixel pitch for a large façade display viewed from a distance means making a serious investment in sharpness the viewer won't notice.

Resolution depends on the size of the display

The resolution of an LED display is not a fixed value; it is calculated by dividing the display width by the pixel pitch. For example, a 4-meter-wide P4 display has a horizontal resolution of about 1000 pixels. Content should be prepared and optimized for this resolution.

What to look at besides pixel pitch

• Brightness (nits): A low brightness value is enough for indoor applications; more than that tires viewers' eyes. Outdoors, a brightness level that ensures readability in sunlight is required.
• IP rating: The water and dust resistance of displays placed outdoors is documented by IP certification. Depending on the architecture of the installation site, the protection (IP) ratings of the front and rear surfaces may differ.
• Refresh rate: Displays with a low refresh rate show lines when filmed with a camera, which makes this a deciding criterion for stage and event displays.
• Maintenance access: Whether modules are replaced from the front or the back directly determines the mounting method and the support structure design.
• Spare modules: Setting aside spare modules from the same production batch makes it possible to replace modules without color differences, even years later.

Summary

For the right choice, first measure the closest viewing distance and set the pixel pitch accordingly; then choose the brightness based on ambient light and, for outdoor applications, the IP rating. You can find the LED projects we've installed and technical details on our LED display page; for an on-site survey, get in touch with us.