You now have the finished blind width and length. Next you need to calculate the number of folds in the roman blind as it is pulled up. The blind will have standard folds where the folds lie on top of each other when the blind is pulled up.
STANDARD FOLDS CALCULATION
First we need to establish the
The headrail allowance must be sufficient to cover the batten face and allow enough room for the blind to pull up underneath the batten without it hitting the batten/eyelets before it is fully up (with all the folds hanging inline with each other).
As a general rule use an absolute minimum headrail allowance of:
Traditional batten: Batten face + 3.5cm
Headrail mechanisim: Headrail depth + 2.5cm
Please see our BLOG entry HEADRAIL ALLOWANCE EXPLAINED
for more detail
- Deduct the headrail allowance from the finished blind length to give the amount of fabric to be folded.
- Decide on the approximate depth you would like the folds to be when the blind is pulled up*. Folds are usually 10cm to 25cm.
- Divide the length of fabric to be folded by an odd number until you get an answer closest to your ideal depth of the folds.
- The odd number that was closest is now your number of pleat sections and the answer in (3.) is now the depth of your folds.
- The number of rod pockets = (number of pleat sections -1) divided by 2
*Note the depth of the blind when pulled up will be equal to the headrail allowance plus the depth of the fold (one pleat section).
Alternatively try our online calculator.