How much is 1px equal to in cm(centimetre) and pt(points)???

Question

As formula to calculate em is em=pixels/16, in the same way do we have any formula for calculating centimetres or points in terms of pixels ??......

Answer 1

It varies based on DPI (Dots Per Inch). For example, a 1080p TV has the same amount of pixels regardless or whether it is a 19" or a 60" screen.

Answer 2

em is percent of font-size