There are numerous articles about how to measure a fireplace screen.
There doesn't seem to be many articles that address how to choose a Fireplace Screen to fit a particular size room.
Try these suggestions to find the right fire screen for your size room.
To measure for a fireplace screen, measure the width and height of the opening of the fireplace.
Next, determine the size fireplace screen needed to cover the opening.
A fire screen is measured by height and width from the extremes with the fire screen laid flat.
If you want to use a folding fire screen, you will need to allow a minimum of six additional inches on each side to allow for the fold back to the fireplace.
If you are using a mesh fire screen, it will need to be fitted to the inside measurements of your opening.
A single panel orflat fire screen can exceed the measurements of the fireplace opening in height and width as desired.
How big is the room with the fireplace? This is important in choosing the type of fire screen you will want.
What do you want to highlight? Do you want to highlight the fireplace as the center of focus in the room? Do you want to minimize attention to the fireplace in order to make the room appear larger? Do you want to highlight and direct attention to the fireplace but have a small room? All of these can be accomplished with the correct fire screen.
The solution starts with the size of the room and the seating or conversation areas in relation to the fireplace.
For a large room with several conversation areas try these suggestions:

• Be sure the closest seating area is at least six feet away from the Fireplace Screen.
  
• Use athree-fold Fireplace screen to draw the room closer and make it feel a little more intimate.
  
• Use a flat single panel Fire screen to make the room feel bigger and make the fireplace seem smaller.
  
• Use a stained glass or beveled glass three-fold fireplace screen to draw more attention toward the fireplace.
  This will bring the room in closer and feel more intimate.
  Do not use a flat single pane stained glass or beveled glass fire screen with an active hot fire.
  The heat may cause the solder that holds the glass pieces together to overheat and soften.
  This could damage your fireplace screen.
  Use caution with the three or four-fold stained glass screens.
  Do not build too big a fire.
  

For a small room with one primary seating area try these suggestions:

• Be sure the seating area is a minimum of six feet from the fire screen.
  
• Use a flat single panel fire screen to maximize the size of the room.
  
• Use a decorative black wrought iron screen to draw attention to the fireplace while not diminishing the size of the room.
  
• Use andirons in lieu of a log grate.
  This will draw the viewer's eyes further into the fireplace without using any outside space.
  

An old adage says, "Measure twice.
Cut once.
" Take your time to measure and arrange furniture before selecting the right fireplace screen to fit the room.