How to make -
Blackout Roman Blind
Step 2: Calculate the Rod Pocket Positions
Printable Worksheet
Printable Worksheet

You now have the finished blind width, length and a preferred Top Section Size. Next you need to calculate the number of rod pockets on the back of the blind and their positions. This will determine the style and depth of the blind when it is pulled up.


The making process is the same for all 3 styles of blind, the only difference is the calculation of the number of rod pockets and their positions. In our tutorial videos we will be making a standard folds blind where flaps all line up in the up position. If you are making a cascading blind or a blind with an extended bottom flap, see the links at the bottom of the page for some extra information.


First we need to establish the Headrail Allowance

The headrail allowance must be sufficient to cover the batten/headrail face and allow enough room under the blind for the folds to pull up to the correct position..

We use a minimum of 6.5cm for headrail allowance for our headrails. As a general rule use an absolute minimum headrail allowance of:

Headrail mechanisim: Headrail depth + 2.5cm
Traditional wooden batten: Batten face + 3.5cm

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.
  • Divide the length of fabric to be folded by an odd number of fold sections - this will be the fold depth for that number of fold sections.
  • Add the headrail allowance to the fold depth to get the Top Section size.
  • Find the odd number that gives a Top Section size nearest your preferred Top Section size.
  • The odd number that was closest is now your number of fold sections and the answer in (2.) is now the depth of your folds.
  • The number of rod pockets = (number of fold sections -1) divided by 2


  1. When choosing the best Top section size also consider your pattern if using patterned fabric. If possible choosing a depth that gives the best pattern placement when the blind is up.
  2. Adjust the headrail allowance slightly to tweak a Top section size. (never below minimum). Eg when trying to get 2 blinds of slightly different lengths the same size when pulled up, or getting the Top section the perfect size for the pattern.


With the number of rod pockets (3) and fold depth (12.0cm), we can now calculate the rod pocket positions

Try our online calculator to check your figures.


To calculate the rod pocket positions for a cascading blind please use our FREE Cascading Roman Blind Folds Calculator

To calculate the rod pocket positions for a blind with a bottom flap please use our FREE Cascading Roman Blind Folds Calculator

Enter your bottom flap size and a cascade increment of 0. The folds will then all line up with just the bottom flap hanging lower when the blind is pulled up.


Yes that is normal,standard folds form a very slight cascade due to the way the rods and rings stack on each other when the blind is pulled up. The calculation of the rod pocket positions means that if the rods were all pulled up to exactly the same height, all the folds would be exactly inline. (see image)

However that is not how a blind pulls up, the rods and rings stack on each other on the cord which creates a very slight cascade. If you were really wanting to make the folds line up exactly inline you would have to make make an adjustment to your rod pocket position calculation . It would involve making a mock up to see what the slight cascade depth is caused by the type of rod pockets and ring/breakouts you are using. Then recalculating the rod pocket positions to adjust for this. (this is not something we do)

Questions & Comments


Hi there,

Would you mind telling me where you purchased the roman blind stand shown in the video above. i have started working from home and have a number of requests to make roman blinds for other people.

thank you



This is the stand  HERE You will need 2 brackets to hold the blind on it like THIS BRACKET . Because the headrail passes in front of the post you may have to drill another hole in each bracket 

A pair of brackets  HERE a bit cheaper.


Thank you for your great tutorial. I have to make 4 Roman blinds using patterned material, should I cut the face fabric for all the blinds at the same time at the beginning of the project or as I go?


When I make up several blinds in the same fabric I tend to cut the face panels all at the same time to ensure that they all start at the same point in the pattern, as this avoids confusion later. 


HI, I've made 3 blinds already - thanks for your brilliant videos...

I'm now making my 1st b/o blind using rod pockets. My blind is 170W by 142 drop - is this too long to use the b/o lining sideways? (just reading your comment above)...if so, would I join the panels in the same way as fabric? Just concerned there will be 2 lines of sticking showing through the b/o lining.

Thanks in advance


Roman blinds really are best when they are one width or less wide. When you try to make big roman blinds they become more difficult to make and keep square and in this case you will come up against some problems with the blackout. A large Roman blind is not always the best solution for a window.

Your blackout will probably only be 137cm wide so wont be wide enough to use it sideways. 

When you make any stitching in the blackout lining it will create small pinpricks of light when the blind is down. Your joins in the blackout will make lines of pinpricks of light, as will the stitch lines for rod tape  or rod pockets. 

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