Convert from point [Britain, US] to em

Unit Definition (point [Britain, US])
The unit of measure for the height of type, defined as 1/72 of an inch* or 0.3527777778 mm (*small differences occur in this unit between countries, the variables lying between 0.188 and 0.4mm)

Unit Definition (em)
The em is a printer's unit of relative distance. One em is the height of the type size (in points) being used. If 12 point type is being set, then one em is 12 points, and so on.