Photoshop pixels to Android dp -

i'm trying convert text dimension psd representation android dp format. on internet there resources explain dp, sp how convert them still don't understand do. need example case.

let's have psd 3 lines of text different dimensions:

18px font - ? dp 21px font - ? dp 28px font - ? dp 

which dimensions choose handheld device if want maintain same apparent dimension? how make gui similar psd template?

taken this thread

• px 1 pixel.
• sp scale-independent pixels
• dip (dp) density-independent pixels.

use

• sp font sizes
• dp else

from android developer

+---------+-------------+---------------+-------------+--------------------+ | density | description | units per     | density     | same physical size |  |         |             | physical inch | independent | on every screen    |  +---------+-------------+---------------+-------------+--------------------+ | px      | pixels      | varies        | no          | no                 |  +---------+-------------+---------------+-------------+--------------------+ | in      | inches      | 1             | yes         | yes                |  +---------+-------------+---------------+-------------+--------------------+ | mm      | millimeters | 24.5          | yes         | yes                |  +---------+-------------+---------------+-------------+--------------------+ | pt      | points      | 72            | yes         | yes                |  +---------+-------------+---------------+-------------+--------------------+ | dp      | density     | ~ 160         | yes         | no                 |  |         | independent |               |             |                    |  |         | pixels      |               |             |                    |  +---------+-------------+---------------+-------------+--------------------+ | sp      | scale       | ~ 160         | yes         | no                 |  |         | independent |               |             |                    |  |         | pixels      |               |             |                    |  +---------+-------------+---------------+-------------+--------------------+ 

px pixels - corresponds actual pixels on screen.

in inches - based on physical size of screen. 1 inch = 2.54 centimeters

mm millimeters - based on physical size of screen.

pt points - 1/72 of inch based on physical size of screen.

dp density-independent pixels - abstract unit based on physical density of screen. these units relative 160 dpi screen, 1 dp 1 pixel on 160 dpi screen. ratio of dp-to-pixel change screen density, not in direct proportion. note: compiler accepts both "dip" , "dp", though "dp" more consistent "sp".

sp scale-independent pixels - dp unit, scaled user's font size preference. recommend use unit when specifying font sizes, adjusted both screen density , user's preference.

check out this thread aswell. (changing px dp programmatically)