Pixel to Centimeter?

Question

I just want to know if the pixel unit is something that doesn\'t change, and if we can convert from pixels to let\'s say centimeters ?

Answer 1

As far as I understand it, a PIXEL is:

Picture Element

thus it depends on two things:

(a) Resolution (b) Physical Screen size

Thus if you divide screen size by resolution, this should give you CM per Pixel.