72 points = 96 pixels = 13 characters = 1 inch
Microsoft is wrong about the layout rules for their own flagship program, Excel. Their conversions between points, pixels and characters boil down to this:
72 points = 96 pixels = 13 characters = 1 inch
13 characters.... what? 13 capital letters in 10 point Arial fit nicely in a 96-pixel-wide column. If the column width is in characters, then one would think Excel would change the character count with font size, but it doesn't. Well, it will if one changes the default font size (Tools/Options, yada yada, and restart Excel) but then a 22 point default font gives a default column width of 8.47 (136 pixels), and the apparant cell width accomodates fewer than 7 characters and just about 4 em dashes. I still don't understand how the character count is calculated, however, this seems quite solid for height and width:
At 100% print scale 72 points = 96 pixels = 1 inch
Of course, the down side of that is one can't draw a rule thinner than .0138" without zooming the print scale and thereby suffering serious typographic layout inconveniences.