ArcGIS uses software scalable fonts to display text. This allows the labels, annotation, and map text to be drawn at different map scales while maintaining their display properties. An example of a software scalable font is Arial (Open Type).
When displaying text, the actual height of a text character will vary from font to font. A type character is measured from the top of its ascender line to the bottom of its descender line:
The character cell is a box that surrounds the individual character. If the text character does not occupy the entire height of the character cell, the character will appear smaller than the specified point size.
Measuring text font size using points
A point is the standard unit of measure for character height and width. Points can be entered in whole and half sizes. The following conversions can be used as a reference guide for point sizes.
Point to Inch Conversion Table
12 (1 pica)
72 (6 picas)