What is the difference between “px”, “dp”, “dip” and “sp” on Android?
What is the difference between:
pxdipdpsp
on Android?
Android
android-layout
- asked 8 years ago
- G John
3Answer
From the Android Developer Documentation:
-
px
Pixels - corresponds to actual pixels on the screen. -
in
Inches - based on the physical size of the screen.
1 Inch = 2.54 centimeters -
mm
Millimeters - based on the physical size of the screen. -
pt
Points - 1/72 of an inch based on the physical size of the screen. -
dp or dip
Density-independent Pixels - an abstract unit that is based on the physical density of the screen. These units are relative to a 160 dpi screen, so one dp is one pixel on a 160 dpi screen. The ratio of dp-to-pixel will change with the screen density, but not necessarily in direct proportion. Note: The compiler accepts both "dip" and "dp", though "dp" is more consistent with "sp". -
sp
Scale-independent Pixels - this is like the dp unit, but it is also scaled by the user's font size preference. It is recommend you use this unit when specifying font sizes, so they will be adjusted for both the screen density and user's preference.
More info can be also be found in the Google Design Documentation.
- answered 8 years ago
- Community wiki
I will elaborate more on how exactly does dp convert to px:
- If running on mdpi device, 150x150 px image will take up 150*150 dp of screen space.
- If running on hdpi device, 150x150 px image will take up 100*100 dp of screen space.
- If running on xhdpi device, 150x150 px image will take up 75*75 dp of screen space.
The other way around: say, you want to add an image to your application and you need it to fill 100*100 dp control, you'll need to create different size images for supported screen sizes:
- 100*100 px image for mdpi
- 150*150 px image for hdpi
- 200*200 px image for xhdpi
- answered 8 years ago
- Community wiki
1) px Pixels - point per scale corresponds to actual pixels on the screen.
2) in Inches - based on the physical size of the screen.
3) mm Millimeters - based on the physical size of the screen.
4) pt Points - 1/72 of an inch based on the physical size of the screen.
5) dp Density - independent Pixels - an abstract unit that is based on the physical density of the screen. These units are relative to a 160 dpi screen, so one dp is one pixel on a 160 dpi screen. The ratio of dp-to-pixel will change with the screen density, but not necessarily in direct proportion. Note: The compiler accepts both dip and dp, though dp is more consistent with sp.
6) sp Scale-independent Pixels - this is like the dp unit, but it is also scaled by the user's font size preference. It is recommend you use this unit when specifying font sizes, so they will be adjusted for both the screen density and user's preference.
Take the example of two screens that are the same size but one has a screen density of 160 dpi (dots per inch, i.e. pixels per inch) and the other is 240 dpi.
Lower resolution screen Higher resolution, same size
Physical Width 1.5 inches 1.5 inches
Dots Per Inch (“dpi”) 160 240
Pixels (=width*dpi) 240 360
Density (factor of baseline 160) 1.0 1.5
Density-independent Pixels 240 240
(“dip” or “dp” or “dps”)
Scale-independent pixels (“sip” or “sp”) Depends on user font size settings same
- answered 8 years ago
- Community wiki
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