Mobile Web Pixel Basics

PX:css pixels logical pixels, abstract units used by the browser

DP (Android), PT (IOS):device independent pixels devices-independent pixels, logical pixels

DPR:devicepixelratio device pixel scaling ratio

DPi: Ink dots that can be sprayed on the printer per inch (printing industry)

PPI: The number of pixels per inch of the screen, which is the pixel density in units of inches

At present, in the computer display device parameter description, the meaning of the two expressions is the same.

Calculation formula: Take IPhone5 as an example,

PPI =√ (11362 + 6402)/4 = 326 PPI

	ldpi	mdpi	hdpi	xhdpi
Ppi	120	160	240	320
Default zoom ratio	0.75	1.0	1.5	2.0

Note: The retina screen (Gaoqing): DPR is greater than or equal to 2.

Mobile Web Pixel Basics