What Sizes Are Available For Standard Displays Modules

Standard display modules are offered in a short, stable list of diagonals: roughly 0.96, 1.3, 1.54, 1.8, 2.0, 2.4, 2.8, 3.2, 3.5, 4.3, 5.0, 7.0 and 10.1 inches, each tied to a handful of standard resolutions. Sizes between those points exist, but they are tooling projects rather than catalog items.

Why the list is short

Panels are cut from a mother sheet of glass, and every cut has to divide that sheet efficiently. A diagonal that leaves unusable slivers raises the cost of every panel on the sheet, so suppliers converge on sizes that tile well and on resolutions that match the channel count of readily available driver ICs.

The rest of the module follows the same logic. COG bonding tools, FPC dimensions, connector footprints and test fixtures are all built around those combinations. Standardising them is what makes a catalog part inexpensive and quick to restock, and it is the reason a buyer who needs 2.2 inches pays more than a buyer who accepts 2.4.

Common pairings

The table below shows the pairings that appear most often in supplier catalogs. Treat it as a starting point for the conversation, not a substitute for the datasheet, because two modules with the same diagonal can differ in active area, bezel and interface.

Diagonal	Typical resolution	Typical interface	Common use
0.96 in	128×64	SPI, I2C	Mono status displays, wearables
1.3 in	128×64, 240×240	SPI, I2C	Handheld instruments, wearables
1.54 in	240×240	SPI	Compact meters, appliance panels
2.0 in	240×320, 176×220	SPI, 8-bit parallel	Portable instruments
2.4 in	240×320	SPI, 8/16-bit parallel	Handheld terminals, meters
2.8 in	240×320	SPI, RGB	Industrial front panels
3.5 in	320×480, 480×320	SPI, RGB	HMI, test equipment
4.3 in	480×272	RGB	Appliance and vehicle panels
5.0 in	800×480	RGB, MIPI	Medical and industrial monitors
7.0 in	800×480, 1024×600	RGB, LVDS, MIPI	Kiosks, control panels
10.1 in	1024×600, 1280×800	LVDS, eDP	Terminals, instrumentation

Active area versus outline

A 5-inch module does not occupy 5 inches of your enclosure. The quoted diagonal describes the active area, and the module adds a bezel, a frame and a flex tail. Budget the mechanical space from the outline drawing rather than from the diagonal.

The active area itself follows from the diagonal and aspect ratio. For an aspect ratio a = W ÷ H, width is d × a ÷ √(a² + 1) and height is width ÷ a. A 5-inch 16:9 panel therefore measures about 110.7 by 62.3 mm, while a 5-inch 4:3 panel measures about 101.6 by 76.2 mm. Same diagonal, very different footprint, which is exactly the trap that catches a design late in the schedule. Datasheets also round the diagonal, so two parts sold as 5-inch can differ by a millimetre or two of active area. The drawing is the only reliable source.

Reading distance and text size

Resolution only matters in relation to how far away the viewer stands. Convert the character height you need into an angle: a character of height h at distance d subtends 2 × arctan(h ÷ 2d). At arm's length, a 3 mm character subtends roughly 24 arcminutes, comfortably legible; the same character at two metres subtends about 5 arcminutes and becomes unreadable regardless of pixel count.

A practical route is to fix the angular target first, then derive the millimetres, then choose the diagonal whose active area accommodates the resulting layout. Choosing the diagonal first and squeezing the layout afterwards is how panels end up with text that is technically present and practically illegible.

Interface follows size

Small modules generally use serial buses. SPI needs four signal lines plus power and is adequate for static content and modest refresh at low colour depth; I2C needs two lines and suits occasional updates rather than animation. Both become limiting as the pixel count rises, because the clock rate has to carry the whole frame.

From roughly 4.3 inches upward, parallel RGB, LVDS or MIPI DSI take over. RGB needs a wide bus and a controller with a dedicated display peripheral. LVDS and MIPI reduce the wire count but require a compatible host, so the interface decision usually constrains the processor choice as much as the panel choice. Buyers browsing the TFT display collection will see the same diagonal offered with several interfaces for this reason.

Stack-up and thickness

Diagonal and resolution describe the front of the module; thickness comes from everything behind it. A transmissive TFT carries a backlight unit, and the type of unit changes the depth as much as the panel does. Edge-lit backlights keep small modules thin and suit handheld devices, while direct-lit arrangements distribute light more evenly across larger areas at the cost of depth.

Adding touch, a cover glass or an optical bonding layer each adds to the total stack, and each interface in that stack is a potential source of reflection. When the mechanical budget is tight, ask for the assembled thickness rather than the panel thickness, and ask which layers are bonded and which are air-gap. The answer decides both the depth and the amount of parallax between the image and the touch surface.

When a standard size fails

Custom sizes make sense when the enclosure is fixed by industrial design, when an unusual aspect ratio is needed to fit a DIN cut-out, or when a standard panel cannot meet an environmental requirement. They do not make sense for a first prototype, because tooling and qualification add cost and delay before the design is proven.

The usual compromise is to build the first units around the nearest standard part, prove the electronics and the user interface, then move to a custom panel once the mechanical envelope is settled. That sequence keeps the schedule short and confines the expensive step to a design that is already known to work. The industrial display range covers most of the sizes that come up in equipment design, including wide-temperature variants.

Checking a quotation

• Confirm the diagonal refers to the active area and ask for the outline drawing.
• Check that the resolution quoted is native, not an upscaled input mode.
• Match the interface to the host peripheral you actually have, not to the one on the eval board.
• Ask for brightness at a stated drive current and contrast at a stated measurement condition^[1].
• Confirm the operating temperature grade and whether the FPC length is fixed or build-to-order.

Standard sizes are a convenience, not a constraint, provided the mechanical envelope is derived from the outline drawing and the readability target is set in angular terms before the panel is chosen.

References

1. ISO 9241-307:2008 — Ergonomics of human-system interaction — Part 307: Analysis and compliance test methods for electronic visual displays. International Organization for Standardization. https://www.iso.org/standard/40102.html