(Cascading Blind)



(all rounded to nearest 0.1cm)
Rod Pocket Layout
Bottom of blind to rod pocket
diagram indicative only - not to scale or propotion



How use this Calculator

  • Enter the following values in cms.
    • Finished Blind Drop
    • Headrail Allowance*
    • Bottom flap depth
    • Cascade section depth
  • Select a number of cascade sections
  • Press "Enter" to calculate
  • Varying the number of Cascade sections and the cascade increment will change the length of the blind in the up position and the top pleat size.
  • The ROD POCKET LAYOUT section below will produce a diagram showing the rod pocket positions

* Please see our BLOG item Headrail allowance explained for more information on headrail allowances.

The bottom flap can be varied in length to your design requirements or made the same size as the cascade increment .

Making your own Blind?

This blind calculator is designed to compliment our free tutorial instructions.

Questions & Comments


Just fantastic - I wish I had found your site before. The calcualtors are amazing and give me confidence to finally make the first cut in my fabric and make a start on 3 roman blinds!


This calculator is brilliant. Thank you so much for sharing it with us

Amanda Larsson

Hello, please could you help me, I've been playing around with the calculator but I still can't seem to get what I need.

I have a 180cm drop, I need the pulled up blind length to be near 30cm and it's is a cascade blind, I can't get the bottom flap to be in the cascade as well!?!?!

Hope I make sense! Thanking you in advance !


Set the bottom flap size to the same as the cascade size .


hi there - this is really great! I have also purchased your video tutorials.

Quick question - when I use the calculator what is the allowance for rode pockets I do I need to add this myself? Also I am assuming that the the measurement is from the bottom of the blind and I do not need to deduct the 2cm hem allowance as per the video?

Many thanks


Hi Kate

This Calculator JUST calculates the position of the rod pockets relative to the bottom of the blind. It does not calculate lining quantities or how to mark the lining as this varies depending on whether  the blind is lined or interlined. The construction and making of the blind is covered in the tutorials.


Hi, can I use this calculator if I only want one a casading at the base so to show contrasting base of blind? Thank you in advance


If you mean something like this where all the folds of the blind will line up, but the bottom flap will hang down lower when the blind is pullled up.

roman blind with bottom flap

Then Yes. 

You can do that if you put a value of 0 for the "Cascade Increment" and enter what ever you want the bottom flap to be longer as the "Bottom Flap Depth" value. 


Your calculator doesn't seem to be working, any idea when it will be back up again?



It is working when we try are you sure you are putting reasonable figure in. If you enter figures that wont work it will come up with an error message.


Oh my word ... this is absolutely fantastic!!!!!! I have just spent hours trying to get my head round making a cascade blind and in desperation turned to my computer ... and found this. Thank you soooooooooooooo much!

Nicola Blackwell

Thank you for this calculation and your fantastic website!

Presumably I need to take of the hem allowance of the face fabric when pinning/marking out the rod pockets on the lining? The measurements that you have given are from the bottom of the actual blind and not the bottom of the lining I think? Thank you


Yes the positions of the rod pockets calculated are from the bottom of the blind.

The linings are not the same on lined and interlined blinds with their bottom at different positions on the blind. So the calculator tells you rod pocket positions from the bottom of the blind.

The tutorials on the website tell you how to make the lining up for which ever type of blind you are making. 


Brilliant website. I have made one blind already which looks great. I now am trying to work out if I can make three separate blinds for a bay window. The lengths are different 230 X 2 and 1 X 270. Is it possible to adjust measurements so that all three have the same length when pulled up. Hope that makes sense. I am using a blind kit with 5 rods


I'm afraid we havent the time to go through the iterations to try and match up cascading blinds of different lengths.

The easiest way (not cascading) but with normal folds is to make the pleat sections 20cm (as 40cm is the difference between your blinds). Using a 10cm headrail allowance try using our standard blind calculator. One blind with 11 sections and the other with 13.  Note you will need 6 rods in the longer blind and the blind will be 30cm high when pulled up.

Jill G

Wonderful website, saved me hours of calculations! Thanks

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