(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


This is incredibly helpful. I'm making my blinds with romaman blind tape, could I just ask if the measurements given (from the bottom of the blind) are to the actual stitching line or would I need to make a small adjustment?


It is to the stitch line you make with the rod pocket or the stitch line you attach the tape on with (note you usually only attach the tape with one line of stitching). This is because the stitch line is the point the blind is being pulled up on.


Great tool, thanks! How do I calculate the fabric requirements for the 268cm cascade blind?


The fabric required for a blind depends on it's length when down and whether it is Lined, Interlined or Blackout. Whether it is cascade or standard folds does not affect the fabric qty. 

We have full written tutorials on the website FREE to read that fully explain the fabric calculations. Plus a FREE fabric Qty calculator to check your calculations.

Lined Roman Blind Tutorial

Interlined Roman Blind Tutorial

Blackout Roman Blind Tutorial

Roman Blind Fabric QTY Calculator

Sarah patterson

Hi love your page but I’m having problem with a cascade blind the pelmet is 11inch deep and blind is 116drop and I want the first fold a inch below bottom of pelmet can you advise me what to do please


Happy New Year! Awesome videos - thank you so much for sharing so many invaluable tips of the trade.

I know you can tweak the head rail allowance, but would it still work if I stretched it to 15cm? I have a fabric with a big design and ideally I'd like to show the full pattern in my top section. It's a long window so the depth when drawn isn't an issue. Many thanks, Jane.


Glad you’re enjoying the videos! I have done similar to what you are asking with blinds before (when one was mounted outside the recess, approx 40cm above ) and my customer wanted the top section to sit just below the top of the recess. My top section was approx 47 cm but I didn’t make rod pockets 80cm apart. 

Good luck with your project.



Thank you so much Cindy and for getting back to me super quickly too. Yes, that sounds just like what I'm trying to do. So it's reasuring to know it can be done. I'll send you some pics when I've finished. Have a great weekend.

EIleen C.

Is there a way to change the cm to inches without figuring each one?

Allison Young

Hello. My friend’s window recess width is 192cm and she would like one Roman blind, not two. Do you believe that the 192cm width is too wide for one track. I do not want to commit my friends money to buying one track if, when hanging the blind, it’s too big to be practical

Many thanks in advance


No problem with 1 blind that width but make sure that you buy a geared mechanism to allow for the extra weight. Cindy

Tina W

When making a cascading blind using the lining to make the rod pockets, please can you tell me how much I have to add on a how to do it.

Many thanks.


The calculator gives you the rod pocket positions on the blind. Then follow the tutorial instructions for placemnet of the rod pockets on the lining. Note the linings are different on a lined blind compared to a blackout or interlined, so you need to follow the specific instructions in the tutorial.



Just to say thanks for the great calculators they definitely make things easier. I was just wondering why we are not able to print the calculations off now?


That facility is not currently coded into the website


I have just finished making 11 Roman blinds for my sons new home and every one turned out perfect first time and they are so happy with them. Absolutely brilliant website and so easy to use, wish I’d seen it years ago.


thanks for this got there in the end. Would be great to have a feature to be able to adjust the blind length when pulled up and work from there, my window has a top opener so taken me a while to work out the calcs for it to sit in the right place against the frame for neatness :)


i used these measurements and did not get a cascading blind


What measurements did you use for the rod pocket positions and what figures did you enter into the calculator for

Blind length, headrail allowance, bottom flap depth, cascade increment and number of cascade sections? If your blind isn't cascading did you use our other Standard Folds Calculator  where the folds align rather than this cascade calculator.


Wow, I’ve made many roman blinds in the past and have spent many an hour working out calculations for fold/rod measurements, often mocking them up on spit and cross paper before committing to cutting and sewing.

This system is so easy to use. I’ve tried it with a number of different measurements and it’s it’s been absolutely perfect.

Thank you so much for sharing this with others.


Sally here I wasn’t planning on a different depth for the bottom flap I’d left that input realise that I should have inserted a zero! Funny how it works well with the previously missing digit!

Sorry to bother you, wish me may get a photo, depending on the outcome!


We would put the bottom flap the same size as the cascade increment then the cascade depth would be the same all the way down, rather than the bottom flap pulling up inline at the bottom.


I’m trying to make a blind for the first time and kind of like the idea of the cascading blind option, but I can’t seem to use your calculator. Sorry to sound so dim but can you help please? The finished length is only 125cm, is that too short for the cascade option?


I don’t know how old your question is sally but any size blind can have cascades it’s just the shorter the blind is the less rod pockets are needed. I’d suggest 3 cascades (4 rods) ????

Walter Baggins

Thank you so much for this calculator.....I’m on my sixth Roman blind and each one has worked out perfectly with lovely cascades.


That's great. Don't forget you can send a photo, we all love to see what everyone else is making. 


Fantastic web site calculator. I can now make my cascade blind with confidence. Thank you so much.


Hello all, the blind I am making is a dress blind so will never be used. It needs to be 14" when folded up. Any idea how I work out the pleats? I have made the blind 53" drop but can ajyst that. Thankyou


There are pleat calculators on the website, for a standard folds blind and a cascading blind. 


Does the cascading blind sit flat when fully down?

Thank you!

SewHelpful:   yes

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

Ask a Question

Note this service is only for those who have purchsaed a video passcode
Drag & drop images (max 3)