(all folds inline when pulled up)  



Blind Layout

Bottom of blind to rod pocket
diagram indicative only - not to scale or propotion



How to use this calculator

  • Enter the following values in cms.
    • Finished Blind Length
    • Headrail Allowance*
  • Select a number of Fold Sections (must be an odd number)
  • Press "Enter" to calculate
  • If necessary change the number of Fold Sections and/or headrail allowance and recalculate until you find the best "Top Section length" for your blind.
  • Varying the Headrail allowance will help you get the "Top Section" depth right. (Caution: If you make the headrail allowance too small the blind may not pull up properly * )
  • Note the more fold sections you use the thicker the blind will be when pulled up. (using too many may cause problems, with the blind sticking outwards when pulled up)

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

Making your own blind? Learn how to get a professional finish

This blind calculator is designed to compliment our free tutorial instructions on how to make a lined, interlined or blackout Roman Blind. Read the tutorials here to learn our Professional workroom method.

Extra Help & Comments

Claire Evans
The enter button on both of your calculators does not seem to be working. I use safari as my web browser.
Sew Helpful
It works when we test it in safari on a mac and an iPhone. What device are you using?
I have NaN in all the boxes except no. of rods, what have I done wrong ?
Sew Helpful
NaN is an error message meaning NOT A NUMBER. It will occur if you enter cm15 etc instead of 15 or 15cm in the input boxes as the calculator thinks you have entered text not a number.

I am making a blind 200cm finished length.
I have used your calculator which suggests 7.5cm head rail allowance and 17.5 cm each Pleat section with 5 rods.
How does this take into account the bottom hem pocket for large rod?
Sew Helpful
The results are for the size of the blind folds. The bottom fold includes the hem. There is a comprehensive FREE written tutorial on the site on how to make a roman blind.
wonderful site,
blind finished measurements
calculations (with a batten 5cm depth)
7.5 head allow, 2 rods, 5 sections of 26.5
my question. Due to the width of the blind (cotton lining plus cotton fabric) do you advise, 3 cords,
ie 1 each end and 1 in middle, so as to hold weight or would 1 e/e be sufficient?
Also can I BUY from your company parts for the blind.
Living in France, thankyou
Sew Helpful
We would use 4 to 5 cords for that width blind, Go to step 8 of the lined Roman Blind Tutorial on the website all is explained there.

Unfortunately we do not sell the blind parts at the moment. 
Heather Tyrrell
I am making a roman blind for sone French doors for a garden room. The dimensions of the door are 14inch x40inch. I am having great difficulties in calculating the headrail and the number of pleats. Should I give up now and get someone to make it for me?
I am also intending to use the same material front and back so the pattern can be seen through the doors and inside. Would this work?
Sew Helpful
Have you looked through the tutorial on the website on how to make a lined roman blind. There is lots of extra info there that explains the calculation. 

You will also see there how we make a lined roman blind. If you are using the same fabric front and back it may look a little odd on the back if your fabric has a pattern, as the lining does not go to the edge of the blind on the back, you would not be able to match the lining panel pattern exactly with the fabric edge on the back. This is because you will be making the rod pockets with the fabric effectively changing the pattern repeat.
it would be great to be able to print out the measurements of each blind once the dimensions are decided.
Sew Helpful
Good idea! We will look into that
My blind is 130cm finished how many rods will I need
Sew Helpful
It's a design decision the more rods you have the smaller the pleat sections. That is up to you to decide.
Hi there, firstly thank you for a wonderful site. I am making 60 x 80cm blind. Just wondering why is the very last pleat so much wider than the others as sometimes when I have finished them the top one overlaps all the pleats so have to adjust it to get it right, always happens. Find it hard to calculate that very last pleat to get it exactly right.
Sew Helpful
All the pleats should be the same size except the top one which is longer. It has to be longer to ensure the pleats stack below the head rail and do not pull up into it when the blind is pulled up. The top pleat is the size of the blind when pulled up ( a design decision). With the calculator you can put in the size of the top pleat section then  vary the number of pleat sections and it will calculate the pleat sizes. Obviously the more pleat sections you have the smaller the pleat sizes will be.
I am trying to make a Roman Blind and finishing length will be 108cm. How many rods do I need and what measurement would I do between each rod?
Sew Helpful
We do not make calculations for people. We answer questions to help people to do it for themselves. You will find extra information on how to work it out in the how to make a lined Roman Blind Tutorial on this website.
Hi there. I have a window with 160 drop. The windows are inward opening and in a recess. I only have ceiling to top of window height as 18cm. Could you advise me whether it would be possible to make Roman blinds or do I not have enough clearance above the open window? I was concerned that they might end up very bulky. I have some Laura Ashley linen material which is very thick. Also I have never made blinds before!!!!!

Any advice greatly appreciated!
Sew Helpful
We are thinking with the number of pleats you will need to keep the blind above the window and the thickness of the fabric, the blind will end up too bulky. We would look at other options, roller blind, curtains etc.
Tracy Challacombe
My width of material is 145cm, I need a width of 153cm cut material for my finished blind width of 143cm. I know you don't join down the middle, so how much should you have either side of the main central panel when adding to the width of material. I hope this makes sense? Many thanks Tracy
Sew Helpful
For a lined blind your fabric panel needs to be the finished width of the blind plus 10cm which you have calculated. How much fabric you will need depends on if you have a plain or patterned fabric. Step 6 of the How To Make A Lined Roman Blind Tutorial explains the making up of the  fabric panel and it also directs you to mini tutorials on how to join plain fabric or patterned fabric. The plain fabric joining video uses a 2cm seam allowance on each panel, the patterned fabric join will depend on the pattern. Take a look at the tutorial and the videos in the mini tutorials.
Hi, i'm looking at making a 9 pleat blind but am concerned about how this will work, is 9 pleats too many? my sizes are blind drop 104, with a 5 headrail allowance and pleat length 11...
Sew Helpful
Its hard to comment without seeing the window and knowing what you are trying to do. But we would think a max of 7 pleats for that drop would be more appropriate.
This is my 1st attempt at making a roman blind. I want it to sit inside the recess of the window & my blind measurements are 68cm wide x 112cm drop. I've been trying to work out the fold measurements & I think that with a headrail allowance of 7cm, I could have pleat sections of 15cm depth or with a headrail allowance of 7.5cm, I could have pleat sections of 9.5cm depth. I note that you say folds are usually 10-25cm but I wondered if this mattered with a small window. Could you please advise which would be better
Sew Helpful
 9.5cm folds should work. Without seeing the window we don't know which will look better. With those figures one will have a top section (blind size when pulled up) of 22cm and the other 17cm. Obviously the 17cm wiil have 2 extra rod pockets and consequently 4 extra panels of fabric when pulled up, so may stick out quite a bit more when up. 

Put a bit of paper 22cm wide and 17cm up at the top of the window and see which one you think will look best. 
linda mann
Hi My finished blind would be 175cms drop and 108cms wide. would 30cm fold depth be too big - top section would be 35cms. This calculates at 7 pleat sections and only 3 rod pockets, which does'nt seem enough for a big blind. Am I calculating it wrong ?
Sew Helpful
Yes it is wrong, you would actually be making a longer blind with those figures.

30cm pleat sections x7 = 210cm plus 5cm on the top one (which is 35cm) makes a drop of 215cm. I think you have calculated incorrectly.

Going for a 35cm top section, It would be a top section of 34cm with 23.5cm pleat sections (6 x 23.5) + 34 =175cm rounding to nearest half centimetres. Have a look at your calculation method again.
Hi, My concern is the headrail. I have given 10 cm for this allowance but the wood im using is 5cm x 5cm. With the depth of the eyelets it still wont measure to 10. I am thinking i can pull the blind up to the desired place but just want clarification this will be ok. I chose 10cm as i put in a calculation for a cascade blind, and this figure was suggested. It looks fine after being pinned up and folded to see what it would look like, i am just concerned when i pull up the rods they will want to go up to the eyelet depth.
Sew Helpful
You are thinking right!

10cm allowance is good for your 5cm deep headrail face. Dont worry about there being some extra space to the eyelets, the blind will only pull up as far as you pull it. So you just pull it up until the pleats are where you want them and hold it in that position, you don't have to pull it up with rods tight to the eyelets.

Your headrail is deeper than most, our wooden ones are 3cm deep. The calcuator uses a minimum of 5cm for the headrail in it's calcuation.
Thank you so much for your fantastic site!
My blind measures drop 46 inches. How many rods should I use. Thank you
Sew Helpful
That is a design decision you need to make. The more rods you use the smaller the folds will be.
Julie S
Hello, I am making a blind with a finished length of 145cms x 145 width. My fabric is 140 wide so I will need to join fabric to each side. Can you advise on what width you would add to each side to get the best look. I am also thinking that I could potentially add a strip of complimentary coloured fabric rather than match the fabric. (The pattern repeat is 87 cms.) if I were to add 2 strips each side, in your opinion do you think this can look good? Just wondering if you have done this before.
I don't want really shallow folds, do you think 2 rod pockets is ok? Top pleat 33 and others 28 on this size of blind? Many thanks for your much appreciated advice.
Sew Helpful
We have made blinds with a 10cm wide contrast fabric on each side and they looked nice. It really is a design decision you need to make though.

Your pleat section sizes again is a design decision you can only make looking at the room and the window. Those pleat sizes would be too big for us though we would go smaller.
My finished length of blind is 116 cms, headrail 4cms. I chose 7 pleats but it is coming up as error even if I choose more or less pleats. Please help
Sew Helpful
The headrail allownace is NOT the size of the headrail, you have to allow extra room beneath the headrail or the blind will not fully pull up. The online CALCULATOR uses a minimum of 5cm for the headrail allowance that is why you are getting an error message. If you read the tutorial STEP 2 it explains the headrail allowance.

I'll put a note the calculator uses a minimum of 5cm in the text - as in the tutorial. 
Hennie K
Hi, I've made many blinds before but i'm just about to start my largest one yet- the drop is 260cm, with a width of 119cm. As the window is so large i was hoping to get away with a deep pleat as light isn't an issue- so i choose 9, 28cm pleats. To make sure this would be suitable i put it in the roman blind calculator but it comes up with an error. so, perhaps i should use 11 pleats as oppose to 9?

thank you,
Sew Helpful
Not sure why you are getting an error it works when I try it. Did you put the headrail allowance in.

Your example:
260cm Blind Drop
8cm Headrail Allowance
9 sections

gives Top pleat section 36cm
other pleat sections 28cm

or if you were trying to get the top pleat section 28cm try something like (make sure 6cm is enough for your headrail allowance)

260cm Blind Drop
6cm Headrail Allowance
11 sections

gives Top pleat section 29.09cm
other pleat sections 23.09cm

tweak the headrail allowance down to 5cm and you will get closer to the 28cm top pleat section but make sure 5cm is going to be enough.

It seems to come up with an error if you put a headrail allowance of 4cm or less - in case anyone else is wondering why it's not working as expected.
Sew Helpful
Yes the calculator uses a minimum of 5cm (as per the website tutorial instructions on how to make a roman blind)

There is a note about the 5cm in the explainatory text alongside the calculator .
Hi great site you have here :)
Could you please help I'm making blinds 345cm long how many rod pockets do I need to make it about 25cm of fabric showing when blind is pulled? Need the folds stacked on top quite close together as it is so long.. Many thanks Jade
Sew Helpful
Hi Jade sorry but we don't make calculations for people (we would be inundated).

We're not sure if a roman blind like that will look right for a window that big. With the dimensions you have given it could be very bulky and sticking out at the top when pulled up.

To calcualte the number of rod pockets 

Put your hearail allowance into the calculator and blind drop. then vary the numbe of pleat sections until you get the top section (25cm of fabric showing when blind is pulled) the size you want. You will probably need something like 17 to 19 pleat sections giving you 8 to 9 rod pockets.

(We dont know the fabrics you are using or the window but this blind is not something we would make as we feel it would be too bulky when pulled up and probably wouldn't look right.)

how many pleats in in a roman blind 101.6 drop 46.99wide
Sew Helpful
We do not make calculations for people. We offer help to explain the information we've put here to make your own calculation.
How do I calculate for cascading roman blinds
Sew Helpful
I'm afraid I haven't written that tutorial or made that calculator yet. 

I cannot make any sense of the calculator, if I enter the measurements wrongly I get NaN if I enter them correctly I get ERROR.

There are lots of favourable comments so why is it not working for me?
Sew Helpful
Are you trying to use a headrail allowance of less than 5cm? That would give an error message.
Fantastic site, saved me hours of calculations. Thankyou.
Im making a very small blind, headrail length 7cm, window 89.5wx 86L because its a small window I want as much light as possible so have gone with 7 pleats the calculator comes up with a very long 10.287----- size of pleats if i round it up to say 10.3 will it matter ?
Sew Helpful
Rounding to the nearest mm is going to be no problem but your figures don't sound right to me. 

7 pleat sections  x  10.3  = 72.1 plus headrail of 7cm comes to 79.1 blind length

giving 6 pleat sections of 10.3cm plus top section of 17.3cm but a blind length of 79.1cm NOT the 86cm you say.

I cant see how you came to these figures with the calculator. When you put your figures into the calculator it comes up with

pleat sections 11.285cm
top section 18.285cm 
Claire jones
Hi. I'm making a roman blind 251 cm in drop. I 've allowed a head rail allowance of 8cm to be in the safe side - my metal head rail is 3.5cm. I've calculated that I can either have 9 pleats at a depth of 27cm with 4 rod pockets or 11 pleats at a depth of 22.09 cm with 5 rod pockets. You say that usually the pleats are a max of 25cm. Is it better to go for more or less of pockets? Thinking about being bulky at top/ blind being too heavy to pull up/ ensuring it's strong enough. Is there a reason not to have pleats more than 25cm?
Sew Helpful
An extra pleat will make no real difference to the weight pulling up. The bulk at the top is going to be dependent on the weight and bulk of you fabric, linings and interlings you use. Our guidance is based on people making standard sized blinds and is not a limit it is just a guide based on our experience.

There is no reason you can't make the pleats bigger than 25cm. Your 250cm drop is not a standard sized blind, pleat size is a design decision that mainly affects the depth of the blind when pulled up and its bulk,  all windows are different. You just need to look at the options and make a judgement.
The calculator isn't working. i put in my drop of 147cm and headrail allowance of 4cm, number of pleat sections 9 and pressed enter. the only answer the calculator gives me is 4 rod pockets (which I already knew) the depth of pleat boxes both say ERROR.

I have tried a different number of pleat sections but it still just says ERROR.

also as I have a 13cm border around the bottom and sides of the blind should I leave a little more of the bottom edge showing to balance with the sides?

Would appreciate your advice. Thanks
Sew Helpful
If you read the information to the right of the calculator it tells you the calculator uses a  minimum headrail allownace of 5cm. That is why you are getting an ERROR message when using 4cm.

I have added the minimum 5cm in red to the calculator to make it more obvious. 
I am making two Roman blinds one is 131cm long and the other is 133cm long - my issue is I have two small opening window at the top of each window and, despite losing light, I want the blinds to hang over these parts of the windows. Basically one blind needs to hang at 409cm and the other 500cm to cover both the small windows, the blinds are in a small room near each other. I'm struggling to work the calculations ie how many rods and where to have the folds to allow for this - can you help please?
Sew Helpful
We don't make calculations for people. (we'd get too many requests). You've got a couple of options here.

1. You vary the headrail allowance decide on an appropriate pleat size and make your calcuations to get the blinds the sizes you want. Or

2. Make the blinds a more standard size and then just pull them up to the position you want to cover the smaller window. You also have the option to pull them up even higher to let more light in, open the top window etc.

(I assume you meant 40.9cm and 50.0cm not 409cm and 500cm) 
Hello! I've had a request to make a blind which have larger pleat folds than the standard workings - so the folds are deeper and more prominent. How would you work this out to mark out the rod pockets. Hope that makes sense. Thank you :-)
Sew Helpful
Im not sure what you mean. We would work out the pleats to the required size then mark them out as normal as per the roman blind tutorial.
Hi, I'm making two blinds that will hang side by side, one for a kitchen door and one for the kitchen window next to the door. The kitchen door window has a drop of 115cm and the window next to it has a drop 97cm.
I am trying to calculate the pleat sections and the rods so they will line up together. Is this possible? I'm just wondering whether it would look odd if the rods and pleats don't line up. Could I have the bottom pleat section 18 cm longer on the door?
Sew Helpful
I think you could do this, each blind would be 25cm deep when pulled up.

1 blind 16cm headrail allowance plus 9 x(9cm sections) =97cm

other blind  16cm headrail allowance plus 11 x(9cm sections) =115cm

I assume they will be attached at the same level, as the most important thing to focus on is that they are aligned when pulled up.
Hi, forgive me for being an silly. I am not making my own Roman blind - as My talents in this are are particularly limited! But am trying to decide if I want Roman blinds or curtains.
My question is this....
The length of the blind when fully down will be 172cm. When the blind is pulled up what will its length measure?
I really want to see how much view from the window I will lose! Please help?
Sew Helpful
When pulled up the blind will be the length of the "Top Pleat Section" in the calculator. That is equivalent to the headrail allowance plus 1 standard pleat seaction. (see the diagram)
I've been told that I must measure really carefully when making roman blinds.The drop for my roman blind is 190 cm and I think I'll need five rods. the spacing between pleats has been calculated as 14.1538.... Should I just make one pleat bigger and forget about the 0.15etc?
Sew Helpful
Rather than have different sized spaces we would round all of them to 14 and add the excess into the headrail allowance.
Your tutorial is excellent but I've a question about the headroom allowance that isn't clear.
You explain you must leave enough room for eyelets, battons etc but how much?
Is there a rule of thumb to say X number of battons should need Y headroom allownace on top of the 5cm?
Clearly, 5cm for a big blind with lots of battons isn't going to be enough, but I would like to keep it as small as possible but how to know?
And if you allow too much does that make any difference apart from how it looks?
Thank you very much.
Sew Helpful
Go to our Blog and read "Headrail Allowance Explained" There is info an photos there that wiil help. You will see there is an absolute minimum but using more works fine.

Thank you very much, I didn't spot that.
Just what I needed
Thanks for such wonderful tutorials.
I'm making two blinds for a door and a window that a located side by side in my sitting room. The door has a drop of 212cm and the window, 167cm. I'm having difficulty in getting the measurements for the pleat sections for both the door and window, so the the rod pockets are at the same level on both blinds.
Regards, Ana
Sew Helpful
To get this to work the difference between your blinds (212 -167 = 45cm) will be an even number of pleat sections eg 2,4,6 etc. Therefore in this case I think you will be looking to try and have pleat sections of 45/2 = 22.5cm or 45/4 = 11.25cm.

You now need to go into the calculator with the 167cm length blind and adjust the headrail allowance and number of pleats to get either the 22.5cm or 11.25cm pleat size you want to go for.

Eg taking the 22.5cm pleat size

167cm length blind with 7 pleats, 9.5cm headrail allowance gives Top section of  32cm pleats 22.5cm

You would then put the same figures in for the 212cm blind but with 2 more pleats (eg 9 pleats) that should then work.

212cm length = 9 pleats, 9.5cm headrail allowance gives Top section of  32cm pleats 22.5cm

Effectively the same blind as the 167cm one except with 2 extra pleat sections.

Thank you very much for your help. Much appreciated.
I am a little confused between pleats and folds. Are they the same thing. My blind is 107cm long and I have been told to use 5 rods but don't know how to work out distances between them.
Sew Helpful
A pleat is a section, when pulled up the blind will fold on the fold lines and along the rod pockets.
Thank you for your past help, the blinds turned out brilliantly.
I have another query please. My friend has asked me to make her a blind which it 30 cm wider than the fabric. Would I make a whole width panel in the centre and 2 X 15 cm panels either side? Wondering if the small side panels would look odd?
Thank you for your help
Sew Helpful
We would make it with the 15cm side panels down each side and think they will look fine.

If you look at one of our responses in the lined roman blind tutorial STEP 6, there are some images of a blind with 8cm strips on either side.

Sue pridgeon
I want to make a cascade RB.
Can you do the calculations for me please?
Finished Drop 86cms
Headrail 6cm
7 folds
Cascade 2.5
Top 1/2 section 14.5cm

Many thanks

Sew Helpful
No  -  I'm afraid we do not have time to make calculations for people.

We have made a FREE cascading roman blind calculator on the website though. You should be able to make your calculations using that.
I'm making two blinds, with different drops and I want them both to have same top pleats and I'm struggling to work out spacing. The finished drops are: 192cm and 155cm (this includes 5 headrail allowance). Any help would be most appreciated.
Sew Helpful
5cm headrail allowance is an absolute minimum.

usually the easiest way to to this is make the difference 192-155 = 37cm an extra 2 pleat sections. Then the main blinds would need pleat sections of 18.5. Unfortunately your blind lengths do not work with this as you would need headrail allowances of 25cm. and the blinds in the up positions would be 44cm deep.

The only other way to do this and have the top pleats the same size is vary the headrail allowance of the 2 blinds. Note the pleat sections will be slightly different sizes when the blinds come down. (will this look odd?)

TRy something like.

Enter 155cm blind - 7cm headrail allowance 9 pleat sections = Act ha 7.4cm,  top pleat 23.8cm,  other pleat sections 16.4cm.

Enter 192cm blind - 7cm headrail allowance 11 pleat sections = Act ha 7.2cm,  top pleat 24cm,  other pleat sections 16.8cm.

Thanks for your suggestion, will give it a go. Been pondering for hours!!!
Sorry I'm back again. 155cm and 192cm blind. I think deeper pleats would be better as one of the windows is very large. Do you think the following would look okay/work:

155cm - 7 pleats - 7.3 headrail pleats 21.1 (top pleat 28.4)

192cm - 9 pleats - 9.3 headrail pleats 20.3 (top pleat 29.6)

Thanks in advance for your assistance.
Sew Helpful
Hi Ann

it's a design decision and without seeing the room, windows, their relationship to each other and the fabric we can't say what we think would look ok or best.
Cyndy Hampson
I have been making Roman blinds for years and wish I had found your site sooner. It is fantastic and cuts down on calculation time. Thank you!
Cyndy Hampson
What will happen if I make a blind 196cm wide and 113cm drop to be fitted into the recess of a window.
I am trying to avoid a gap.
Sew Helpful
Sorry we don't understand what you are asking.
I decided to make Roman blinds for my kitchen windows, viewed you very helpful videos, that's where the fun stopped. I live in Australia's capital and have no way of getting some of the simple items required, loads of curtain shops to make them for me but no one supplies the hardware. Your guides in every way made it so simple to put together. Thank you.
Hi, I'm making a roman blind for a French door. 160cm wide x 205cm drop. I would like 25-30cm of fabric showing at top when pulled up.
Using the online calculator it recommended 4rods which I'm not sure sounds correct.
Please can you advise me.
Many thanks
Sew Helpful
Why do you think that isn't correct? Your blind will be 29cm when pulled up and have a 7cm headrail allowance.

There may only be 4 rod pockets but that is 9 pleat sections.

Here are your figures.


Elspeth Moore
Many thanks online calculator made it so easy to complete blinds in faster time.
Tricia Griffiths
Just brilliant - thank you!
Absolutely fantastic site. I have completed two blinds which are amazing, with your help.
I am now making 3 separate blinds for a line of 3 windows (each open individually) in a recessed bay. The left hand length is 114.5cm the right hand side is 117.4cm, a difference of nearly 3cm!
I need them to look level when pulled up, but if I use the slightly different measurements for each blind the folds are different depths. I am using one batten length (191.5cm) for the whole recess.
Have you any ideas that would help me?
Sew Helpful
If you are pulling up off one mechanism/batten then you need all the cord lengths the same and the rod pocket positions the same.

So your only real option is to vary the bottom section depth on each blind. This section is at the back of the blind when pulled up (see where  flap 5 is when pulled up).


To do that we would first work out the dimensions for the 117.4cm blind.  Then make the others the same but with a shorter bottom flap, eg the 114.5cm blind would be the same except its bottom section would be 2.9cm shorter.

Now that would mean when pulled up all the blinds would be in line, on the 117.4cm blind all the folds would hang in line with each other, on the shorter blinds all the folds would hang in line except for the back flap that would be up higher because it is shorter. Now if that bothers you, you can  make the 117.4cm blind so its bottom section is shorter as well at the start then they would all look the same when up (with their back flap pulled higher and not in line), the other blinds will just have even shorter bottom flaps.
Not helping.
Need these with bottom section 12 inches and each section closer to 10 inches
Sew Helpful
Have you tried varying your headrail allowance or number of pleats?
I've used your site in the past for triple pleat lined curtains, cushions and roman blinds. This time I would like to sew a 1cm line of trim at the bottom of the blind and wondered if the best way is to add in 1cm to the material as I don't want it disappearing into the pleats when pulled up.
Sew Helpful
The blind plus the trim needs to be the finished blind length you require from your window measure.

Subtract the depth the trim will hang below the blind from this finished blind length. Then calculate your pleats etc on that new length. Make the blind to that new length, then add the trim to the bottom of the blind. The blind will then pull up with all the folds inline and the trim hanging below the fold line. When down the blind will be the finished blind length you needed from your window measure.
I'm making two blinds for a kitchen and dining room window where the windows are next to each other. One is 127cm long x 185cm wide and the other is 112cm long x 222cm wide.I want them to fall at the same position when drawn up (around 25cm) but I can't work out the measurements in the calculator for this. Please can you help. Also how many cords should I allow for these large blinds? Thanks in advance for your he,p
Sew Helpful
The number of cords will be dependant on what your mechanism specifies. As they have breakout systems nowadays each cord will only be able to take so much load before breaking away.

You need to vary the headrail allowance in each blind.

for example: Entering

127cm long  Headrail allowance 8cm  7 Pleat sections  =   Top section 25cm   HA 8cm
112cm long  Headrail allowance 10cm  7 pleat section    =  Top section 25cm  HA 10.5cm

Of course the pleat sizes of the 2 blinds will be different. 
This calculator and your tutorials saved my blinds and tracks from being thrown out of the window! I had almost given up trying to get the folds in the right places and the correct amount of fabric left showing at the top.
Thanks to you I now have a pair of cascading Romans blinds in adjacent windows that I am so proud of.
Happy days!
Sew Helpful
Thank you Caroline we are really pleased the calculator helped.
What is the maximum number of pleat sections you would recommend. I am making a lined blind (linen and blackout material) and am worried that 11 sections will be too bulky when drawn up. The blind length is c.160cm
Sew Helpful
Should be ok, it might stick out a bit, but ultimately it's quite a long blind and you have to make the blind the size you want when pulled up.
Mafalda Barreto
I have 2 windows in 1 room but they are different lengths therefore each blind will have different number of rods. For this reason I can't make the top pleat of both blinds to be exactly the same measurement therefore do I just work it out as nearest as possible? I have a finished difference of 1.1cm will that be OK? This is based on one curtain length of 100cm having 2 rods and 1 curtain length of 130cm having 3 rods. TIA
Sew Helpful
You can make the top section the same by varying the headrail allowance for each blind.
Joyce Grimshaw
What would you consider to be the right amount of pleat sections, (I am considering 7 or 9) for a blind measurement of 106cm length and 92cm wide?
J Grimshaw
Sew Helpful
It depends on the window, it's setting, the fabric you are using,  how much light you want to block out etc.  Put a tape up to the window and see how big the blind will be when pulled up, (top pleat section) and make a judgement. Also the more pleats the bulkier it will be when pulled up. Either would work we would probably go 7.
Not sure if you received my question.
I have a drop of 160cm and 200cm width, in your professional opinion would 7 or 9 pleats look better
Sew Helpful
It depends on the window, it's setting, the fabric you are using,  thickness of lining/interlining, how much light you want to block out etc.  Put a tape up to the window and see how big the blind will be when pulled up, (top pleat section) and make a judgement. We would go for 9.
I have made a roman blind with a drop of 208cm. Using the calculator I decided on two rod pockets with 5 folds all at 40.6 apart from the first one with an additional 5cm for the head rail allowance. When lowering the blind at different lengths is it usual for it to stop at any point even in between folds or should it sit only on the folds. If I want it lowered to 100cm it sits between folds, is this acceptable as my concern is the folds are too big and I should have gone with 3 rod pockets
many thanks
Sew Helpful
We would of gone for even more than 3 rod pockets (4 or 5). You can lower a blind to any position, we don't ordinarily calculate folds so they sit a  certain way when the blind is pulled to a specific height.
HI, my first attempt at roman blinds! I am covering a large splayed bay window with 3 sections. The each section is 270cm high with the larger middle section being 145cm wide. I'd like to know if this is too big to make a neat roman blind i.e. will they stick out when folded up together and what would be the correct number of folds? Also, will a medium weight curtain fabric combined with thermal lining be too heavy to work properly, I intend using cassette headers.
Sew Helpful
It can be done, put you'll need to make sure you keep everything straight and square.

I'm sorry we don't make calculations for people, with the calculators and online tutorials you can calculate the number of folds needed to give you the desired depth of blind when pulled up. (the depth of blind when pulled up is a design choice there are no hard and fast rules your eye will tell you what looks right). A blind that length with medium fabric and thermal lining will be bulky when pulled up, but it is not possible to say exactly how bulky the folds on your blind will be, obviously the less folds you go for the less bulk.
Mary O'Malley
Hi, This is my first attempt at making Romand blinds and I need to make 2 for the same room. One window drop is 120 cm and the other window drop is 104 cm (the windows are on different walls in the room). Would you suggest having the same amount of rods please? thank you
Sew Helpful
We wouldn't neccessarily use the same number of rods with different windows but we would try to make the blinds a similar size when pulled up.
Like Hennie K I am making a long blind - 233cm drop for an almost floor to ceiling window. I have got 11 pleats and 5 x rods. Top pleat section 28cm (inclucing 7cm for headrail) and then 21cm for the other pleat sections. I think these proportions sound OK?

The main query I have is the width - I am fitting into a recess. I have a dado rail at 170cm from the top and a skirting board taking 6cm up from the bottom. Both of these pieces of woodwork 'infringe' into the window recess.

Should I deduct them from the recess width (so measuring the narrowest point as dado rail to dado rail) or measure the narrowest width as the main recess measurement? The difference is 127cm wide (if recess wall to recess wall) vs 122cm wide (if dado to dado)

I am worried that if I cut & sew for a 122cm finished width a lot of my window frame will show and will the blind will come very close to the actual window pane glass.

It's unlikely the blind will be let fully down very often at all. I was wondering if would be OK to measure as 127cm and let the blind 'crease' around the dado and skirting board when fully let down or will this just look awful? Would it be a nightmare to take-in the blind if does not hang correctly at 127cm wide once made?
Sew Helpful
It doesn't sound like a blind is suitable. We wouldn't crease one around a dado, (the rods won't crease around as they drop past). To reduce a blind width we would take the lining off, remake the lining, make the fabric panel to the correct width etc.
I'm making a blind that is 990mm wide by 2150mm long. I want it to fold up to a maximum of 20cm so as little of the window is covered when up as possible.
I'm struggling to work out the headrail allowance as I feel I should be going for an ex 2 inch batten but these are 44mm square and once I take the rings and eyelets into account I'm looking at over 8cm for the headrail which messes up my pulled up depth using 8 rods.
So...(sorry for long windedness) Can I use a 1 inch square batten or would the 8 rods not stack neatly and the blind would kick out from the bottom when pulled up as not enough depth behind it do you think? I can't use a cassette system as I can't afford to have the chain dangling down so I'll be tucking the cords up out of sight - it will rarely be pulled down and it's actually one of four going side by side (ambitious I know!) Many thanks in advance.
Sew Helpful
When you stack that many folds together they are going to kick forwards a bit anyway. Have you considered using a rectangular profile batten rather than square. We use a rectangular profile batten in the videos, it is 34mm by 18mm.
I ordered a made to measure roman blind 58 cm long. The company made it as a cascade blind unfortunately and now it covers half of my tiny window when pulled up. Is it possible to alter it myself to a standard blind and put another fold in it? Apprehensive as I've never made a blind before
Sew Helpful
You would have to take the lining off, and remake with the rod pockets in different positions and you may need an extra rod. 

Look at our lined Roman blind tutorial, for how to make one. 
I have made a blind using the calculator and I have found that the pleats don't stack behind the top section as I presumed they would be they cascade ever so slightly therefore it looks a little like a cascade blind. I have checked the headrail allowance to see if its the rings stopping it pulling up further but it doesn't seem to be that. My husband seems to think its correct as he says its not technically possible to have them all lined up at the same point behind each other as each rod simply stops at the one before it, which does seem to be the issue as it's about 4mm cascade on each pocket. Have I missed something do you think? Shall I allow a much bigger headrail next time and have a bigger gap between rings and rods when pulled up? Thanks the videos are fantastic. This was my test blind as I'll be making 8 in total and each is 1m x 2.15m (Big windows)
Sew Helpful
There is a small cascade effect due to the rings stacking up on top of each other behind. For the blind to be absolutely in line the cord would effectively have to be passing horizontally throught the rings at the back when pulled up (it is vertical).  

The extent of this mini cascade effect will depend how thick the blind folds are, how the rings/clips/loops stack against each other on the cord when pulled up. Thick rods may also have an effect.

The cascade on ours only tends to be very slight so we just accept it and usually use a headrail allowance of 7cm. This gives us some extra room under the headrail to pull the bottom of the blind up in line with the front.

Your blinds are very long so the more folds you have the greater the effect will compound.  

If the rings/clips etc you are using are consistently causing a 4mm drop per fold when pulled up and you are not happy about it you can always calculate the spacing between the rods to compensate. There is a cascade calculator on the website. 


If it was us and we needed to try and compensate we would look at the cascade calculator and put 215cm length, 7cm Headrail allowance, bottom flap -0.4cm, cascade increment -0.4cm and see what it comes up with. I've tried this with 5 cascade sections (6 rod pockets) and it comes up with a top pleat size of 24.1cm. The blind pulled up length is obviously WRONG because the calculator is not designed to calculate negative cascades. The blind pulled up length would be the top pleat size.

We would then make a mock up with these new rod positions and see if that does the trick. We haven't done this so cant vouch for the accuracy of this method, but it is what I would try first.

Fiona Gordon
I am making a blind for a Narrowboat that is 85cm length and 60cm width. It needs to be no more than 15.5cm finished length when the blind is up which gives fold depths of 8.7cm and 5 rod pockets according to your calculator. Do you think the pleats are too small? It says on your site that they are normally between 10-25cm. The fabric is a light cotton and the blind is lined. The finished length when rolled up is 15.4cm.. Thank you. Your site is fantastic.
Sew Helpful
It should be ok. The fact it is lined rather than interlined will help as well.
Hi I always use your wonderful calculator but could you advise on spacings as I am making a blind where all the pleats are to fold up behind the top pleat. The finished drop is 135.5cm. Trying to get a completed drawn up depth of 19cm or just over if possible. Thank you
Sew Helpful
 I dont understand why you are asking if you know how to use the calculator, I'm afraid we dont make the calcuations for you.
Leanna Adkin
This is brilliant! I've used it a few times and its saved so much time and the working out is the bit I hate! Please don't ever disappear I need this calculator forever! Thank goodness I found you!
Hi I used calculator to make standard roman blind but the bottom fold did not stack behind the others. Width 129 less 6cm headrail allowance divided by 7 made spaces of 17.57. Why did this happen?
Sew Helpful
Without seeing the blind and checking you put the rod pockets in the correct positions it is not possible to say. The botton rod pocket should be 17.5cm from the bottom of the blind.
Hello! When calculating the rod pocket locations, you add 2cm for the hem allowance on the face fabric. Is this distance then the fold line or sew line for the pockets? If you fold at that distance would you need to add 1cm due to it being 1cm from where you sew?
Thanks in advance.

would you add 1cm for each one in addition to the 2cm (hem allowance) due to the
Sew Helpful
This calculator calculates the rod pocket positions from the bottom of the blind.

The tutorials explain the making methods (lined and interlined are different) The tutorials explain and the videos demonstrate how to sew the rod pockets in. You need to refer to the instructions of the actual type of blind you are making.

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