Measure the width of the glass inside each door across in three areas - the top, middle, and bottom.

Use the largest width measurement of the three and add 2 to 3 inches to that number.

Next, measure the height in three areas - the left, middle, and right.

Use the largest height of the three and add4 to 6 inches to that number (2 to 3 inches at the top, and 2 to 3 inches at the bottom).

If the depth of the top frame is less than 2 inches, you must use an outside mount.

Measure the width of your sliding door opening in three areas -top, middle, and bottom.

For an inside mount, take the smallest number of the three and use this as your width measurement.

For an outside mount, add at least 4 inches to your measurement to allow for maximum light gap coverage.

For outside mounts, door heights are measured from top-to-bottom in three areas - left, middle, and right. Remember to start your measurement from where you’ll place the headrail, which is typically 3 to 4 inches above the door.

For inside mounts, simply use the largest measurement. You do not have to add to this measurement.

Measure the window width in three areas - the top, middle, and bottom. Use the largest measurement as your total width.

If you require 2 separate blinds for one window, divide the total width by 2 and use that number for your 2 blind (Ex. 70’’÷ 2 = 35").

If you require 3 separate blinds, divide the total width by 3 and use that number for your 3 blinds (Ex. 90’’÷ 3 = 30’’).