Print the test page in A4 standard format. Place yourself 2.8
meters (or 9 feet) away from the chart. If the test page is in
another format, or if you wish to perform the test facing the
screen, you will have to calculate the distance at which you
must stand facing it, using the following formula: measure the
height of the letter E (first line, 20/200) in millimeters. Then,
divide the value of this measurement by 88. Finally, multiply it
by 6. The result shows the distance at which you must be
placed, in meters.
E.g. (42/88) x 6 = 2.8 m