Take a sturdy tape measure (preferably a metal one) and measure the width of the visible window frame at the top, middle and the bottom of the window frame from wall to wall. Note down the narrowest of the three measurements.
If you can see any obstructions inside your window recess such as a dado rail or tiles at the bottom of the window, then measure in between these obstructions (except for roller blinds - see roller blinds with obstructions inside the window recess below).
Next measure the height (or drop) of the visible window frame, in the middle of the window and at both sides. Note the smallest of these measurements.
When measuring for a blind to fit outside the window recess it is recommend to have an overlap of 100mm (10cm) over each edge of the window recess as shown in the picture to the left.
So measure for an inside recess fit (as shown above) and add 200mm (20cm) to both the width and the drop.
If the window cill protrudes out enough to interfere with the opreation of the blind then only add 10cm to the drop and allow the blind to sit on the cill when it is down.
Using a metal tape measure take the dimensions of 'A' at the narrowest point within the obsrtuction.
As the fabric width of a roller is 34mm narrower than the complete width of the blind. Add 20mm to dimension ‘A’ so that when we make the 34mm deduction for the fixing brackets and ends the fabric will be approximately 14mm narrower than dimension ‘A’ which will allow the fabric to operate freely inside the obstruction. If you have any queries about this then please get in touch.
Inside Recess Size :
In order for the blind to operate freely and smoothly there is a standard deduction of 10mm off the width of the blind (except for roller blinds). On the drop, the deduction is dependent upon the blind. For venetian blinds there is a 20 to 40mm allowance on the drop to allow for free slat operation and movement. For Vertical Blinds there will be a 12mm deduction for the drop to allow the blind to operate correctly.
Exact Blind Size :
The blind will be manufactured to the dimensions you have ordered. So please make sure that you make any extra allowances that are required to miss things inside the window recess such as window handles etc. so that the blind will operate correctly. Note that on roller blinds the fabric width will be 34mm narrower than the overall width of the blind. Unless "fabric size" is selected as an option, in which case the fabric will be the size you specified.
Also note that there is a standard tolerance of up to 5mm during the manufacturing process.
Measuring for the Curtain Width :
Always measure the total width of the curtain pole or track (excluding the finials) – and not the window, unless the pole or track is wall to wall. If you are going to be fitting a brand new track or pole, then it should extend between 15cm (6 inches) and 30cm (12 inches) to either side of the window recess (this is to allow the curtains to be stacked back away from the window opening) and between 12cm (5 inches) and 15cm (6 inches) above the window recess.
Remember to make an allowance for the fabric overlap. This is an additional measurement, normally 2.5cm (1 inch) that will allow the two curtains to overlap in the middle of the pole or track when they are closed.
Measure from one end of the curtain track to the other.
For curtain tracks that overlap in the middle, include the overlap in the overall measurements (see diagram). Measure the width of A + B and then add the two sizes together.
Measure in-between the decorative (finial) ends of the curtain pole.
Measure the drop of the curtains in at least 3 positions along the length of the pole or track as floors and window sills are very often not level. To avoid the curtains dragging across the window sill or floor use the shortest of these measurements.
As a rule, measure the drop from the underside of the curtain rings ensuring the pole can be seen above the curtains. This however does depend on the type of curtain heading you choose (see the diagrams below for the different types of curtain headings and how to measure for each of them).
Before measuring the drop of your curtains, decide whether you want the curtains to fall to the sill, below the sill or to the floor. We suggest that:
If you are using a pole, measure from the underside of the curtain ring to where the curtain is to finish (Approx. 1cm above the floor). If you are using a track, measure from the top of the track to where the curtains are to finish (Approx. 1cm above the floor).
Measure from the top of the pole to where you want the curtains to finish and add 3cm.