Is dp the same as PT?
The documentation says that 160 dp (density-independent) equals 1 inch. And 72 pt is also 1 inch. The nuance here is that 160 dp (or dip ) is roughly 1 inch, while 72 pt is exactly 1 inch. The difference is how android converts both units to pixels, which depends on the screen density of the device.
How many pixels is 1dp?
For this mapping, 1 dp is considered to be equal to 1 pixel on a 160 dpi resolution screen. The corresponding number of pixels can be calculated with the formula px = dp * (dpi/160).