Screen pixel density calculator
Pixel density is the diagonal pixel count divided by the diagonal in inches. Whether it is enough depends on how far away you sit.
inches
Pixel density
163.18PPI
- Dot pitch
- 0.1557 mm
- Screen width
- 23.533 inches
- Screen height
- 13.237 inches
- Megapixels
- 8.294
- Aspect ratio
- 1.7778
- PPI at which pixels become invisible Taking one arcminute of visual acuity at your viewing distance.
- 145.5
- Pixels per degree of vision
- 67.3
Show the working
- Horizontal resolution = 3840
- Vertical resolution = 2160
- Diagonal = 27
- Viewing distance = 60
- diag_px = hypot(3840, 2160) = 4405.81
- Pixel density = 4405.81 / 27 = 163.178
- Aspect ratio = 2160 > 0 ? 3840 / 2160 : 0 = 1.777 78
- Screen width = 27 * 3840 / 4405.81 = 23.5325
- Screen height = 27 * 2160 / 4405.81 = 13.2371
- Dot pitch = 163.178 > 0 ? 25.4 / 163.178 : 0 = 0.155 658
- Megapixels = 3840 * 2160 / 1e6 = 8.2944
- PPI at which pixels become invisible = 60 > 0 ? 3438 / (60 / 2.54) : 0 = 145.542
- Pixels per degree of vision = 60 > 0 ? 163.178 * (60/2.54) * 0.0174532925199433 : 0 = 67.2756
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- PPI = sqrt(width^2 + height^2) / diagonal in inches
- the one-arcminute acuity limit gives about 3438 / distance in inches
A 27-inch 4K monitor is 163 PPI, which is past the acuity limit at a normal desk distance of 60 cm.