How to measure Outer Recess Blinds....

Inner Recess:

Make sure there are no obstructions eg window levers which would affect the smooth operation of the blind.

measure the width from a to b and subtract 1cm for clearance.

measure the length from c to d.

As a precaution take three measurements for the width and length left, right and centre and record the smallest measurement.

Its simple!
A metal tape measure should be used for accuracy.
Just follow these straightforward instructions below: