Measuring your blinds:
Choose whether you would like your blinds to hang inside or outside the window recess. The window recess refers to the gap between the wall in which the window sits. In general, if the window has a deep recess, you can fit the blind inside for a neat finish.
Measure the width in 3 places, ideally using a metal tape measure, and note the smallest measurement.
Measure the length in the same way (taking 3 measurements) from the top of the recess to the sill.
For a window without a deep recess, measure the width of the window and allow about 5cm either side to help block out light.