Fitting inside the recess
Check the width of the recess of your window measuring it in the top, middle and bottom. Pick the smallest measurement and reduce it by 1 cm. This is the width of the blind that you require.
For the drop, measure the height of the recess from the top to the bottom. You don’t need to reduce this measurement, this is the drop of your required blind.
Fitting outside the recess
Typically, you will want your blind to overlap the window frame. The overlap is at your discretion however we usually suggest an overlap of approx. 6 cm on all sides.
Simply add the desired overlap to both your height and width measurements.