Text Size Scale For PC Users
What's the Point?
Text sizes in Bibles and other books are measured in points. A text character is measured from top to bottom of an uppercase text character (usually "E"). There are 72 points to an inch. Text in a Bible with 12-point text size is 12/72" in height (or 1/6").
Comparing Text Sizes
Different monitors and monitor resolution settings will display font sizes differently.
The "boldness" of the text in your samples will probably differ somewhat from the actual print in the Bible you purchase (due to different font styles used in publishing), but the size or height of the text should be close enough for comparison.
Smaller text is easier to read in a two-colum format because your eyes don't have to travel too far to follow a line. Most Bibles with smaller text use a two-column format for this reason.