First of all:

Determine whether you would like your blind to sit inside the window frame (top fixed blind), our outside and above the window frame (face fixed blind).

For Top Fixed Blinds: 

Step One: Measure the horizontal width of the inside of the window frame. This measurement will be the width of your roman blind.

Step Two: Measure the vertical height of the inside of the window frame, with the bottom sitting on the window sill. This measurement will be the finished drop/ length of your roman blind.

Please note: Because the blind sits inside the window frame, the top of your window will still be covered by the blind when it is open.

For Face Fixed Blinds

Face fixed blinds are a great option for when you don't want any light leaking through when closed. You can also choose where you would like the hardware to be mounted on the wall, which helps to give a visual height to your window.

Step One: Measure the horizontal width of the area you wish to cover. We recommend this width to at least be as wide as the far edges of your architrave to avoid light seepage. This measurement will be the finished width.

Step Two: Determine where on your wall you would like your roman blind to be mounted. This location is totally up to you - the higher the mount, the taller your window will appear, and less window will be covered when the blind has been pulled open.

Step Three: Measure the vertical height of the area you wish to cover. This height includes the height of where you would like your mount to sit above the window, as well as how far past the architrave or window sill you would like your roman blind to finish. This measurement will be the finished drop.