Dot pitch

Color displays express dot pitch as a measure of the size of a triad plus the distance between the triads.

Some other types of pixel layout showing how dot pitch is measured.

Dot pitch (sometimes called line pitch, stripe pitch, phosphor pitch, or pixel pitch) is a specification for a computer display, computer printer, image scanner or other pixel-based device that describes the distance, for example, between dots (sub-pixels) of the same color on the inside of a display screen. In the case of a color display dot pitch is a measure of the size of a triad plus the distance between the triads.

Dot pitch may be measured in linear units, usually millimeters, with a smaller number meaning closer spacing, or in dots per linear unit, for example dots per inch, with a larger number meaning closer spacing. Closer spacing generally produces a sharper image (as there are more pixels in a given area). However, other factors may affect image quality, including:

• measurement method not documented, complicated by general ignorance of the existence of multiple methods
• pixel spacing varying across screen area (e.g., increasing in corners compared to center)
• differing pixel geometries
• differing screen resolutions when attempting to judge picture quality
• tightness of electron beam focus and aim (in CRTs)
• differing aspect ratios

Traditionally, dot pitch in displays has been measured on the diagonal, as this gives the most accurate representation of image quality. Starting about the mid-1990s, however, some companies introduced a horizontal dot pitch as a marketing ploy . By measuring only the horizontal component of the dot pitch and ignoring the vertical component, even a cheap, low-quality monitor could be awarded a small-seeming dot pitch.

The exact difference between horizontal and diagonal dot pitch varies with the design of the monitor (see pixel geometry and widescreen), but a typical entry-level 0.28 mm (diagonal) monitor has a horizontal pitch of 0.24 or 0.25 mm, a good quality 0.26 mm (diagonal) unit has a horizontal pitch of 0.22 mm.

The above dot pitch measurement does not apply to aperture grille displays. Such monitors use continuous vertical phosphors band on the screen, so the vertical distance between scan lines is limited only by video input signal's vertical resolution and the thickness of electron beam, so there is no vertical 'dot pitch' on such devices. Aperture grille only has horizontal 'dot pitch', or otherwise known as 'stripe pitch'.

Common dot pitches in monitors

LCD screens

Display resolution	Megapixel	Aspect Ratio	Screen size	Pixel pitch	Pixels per inch
1024×600 (WSVGA)	0.61	128:75	10.1	0.216	117.5
1024×768 (XGA)	0.78	4:3	15 in	0.297 mm	85.5
			17	0.337	75.3
1280×768 (WXGA)	0.98	5:3	15.4	0.262	96.9
1280×800 (WXGA)	1.01	16:10	12.1	0.204	124.7
			13.3	0.224	113.5
			14.1	0.237	107.1
			15.4	0.259	98.0
			17	0.286	88.8
1280×1024 (SXGA)	1.31	5:4	17	0.264	96.2
			18.1	0.280	90.7
			19	0.294	86.3
1366×768	1.05	16:9	14.0	0.227	111.9
			15.6	0.253	100.5
			19	0.308	82.5
1440×900 (WXGA+)	1.29	16:10	14.1	0.211	120.4
			15.4	0.230	110.4
			17	0.254	100.0
			19	0.285	89.1
1400×1050 (SXGA+)	1.51	4:3	15	0.214	118.6
			20.1	0.292	87.0
1600×900	1.44	16:9	13.1	0.181	140.1
			14.0	0.194	131.1
			15.4	0.213	119.2
			17.3	0.239	106.1
1600×1000	1.60	16:10	22	0.296	85.8
1680×1050 (WSXGA+)	1.76	16:10	15.4	0.197	128.9
			17	0.218	116.5
			19	0.244	104.0
			20.1	0.258	98.4
			21	0.269	94.4
			22	0.282	90.0
1600×1200 (UXGA)	1.92	4:3	15	0.191	132.9
			20.1	0.255	99.6
			21.3	0.270	94.0
1920×1080 (1080p)	2.1	16:9	15.6	0.180	141.2
			16.4	0.189	134.3
			21.5	0.248	102.5
			23	0.265	95.8
			23.6	0.272	93.3
			24	0.277	91.8
			24.6	0.284	89.6
			27	0.311	81.6
1920×1200 (WUXGA)	2.30	16:10	15.4	0.173	146.8
			17	0.191	132.9
			22	0.247	102.9
			23	0.258	98.4
			24	0.270	94.0
			25.5	0.287	88.5
			27	0.303	83.8
2560×1600 (WQXGA)	4.09	16:10	30	0.250	101.6
3840×2400 (WQUXGA)	9.21	16:10	22.2	0.125	203.2

_{Bolded screen sizes indicate primarily laptop use.}

Less common dot pitches

The dot pitch of FLC displays (Ferro Liquid Crystal) can be as low as 0.012 mm.

See also

• Pixel

External links

• Dot Pitch Calculator
• PPI calculator, also shows dot pitch
• Megapixel Calculator, also identifies aspect ratio (e.g. 4:3, 16:9), and displays photo and video storage requirements for different formats at a given megapixel number.