When positioning two monitors, use the same height determination as discussed in this article. If you use both monitors equally or use them as one, you should place them centered in front of you side-by-side or slightly turned in toward each other. Some people have a primary monitor and then a secondary monitor they use less often throughout the day. If this is the case, you can have the primary monitor positioned as if it is the only one, and then put the second monitor to the side at a comfortable viewing angle.