CURTAIN Fabric Calculator










How to Calculate Curtain Fabric Quantity

  • Enter your pole or track length
  • Enter the finished length of your curtain.
  • Enter the width of your fabric.
  • Enter the vertical pattern repeat of your fabric, (enter 0 for a plain fabric - see info button regarding half drop pattern repeats)
  • Select whether your curtains are to be just LINED or INTERLINED as well
  • Select whether calculating for a SINGLE curtain or a PAIR.
  • Select your curtain heading type, either pencil pleat, double (pinch) pleat, triple pleat, goblet pleat or cartridge pleat.
  • Enter the depth of your buckram ( enter 0 for pencil pleat heading as you will be using tape)
  • Enter a desired fullness ratio (see info button for recommendations and our tutorials STEP 3 for more info)
  • Decide whether you want to round down the number of widths (see info button and see calculator assumptions note 3 - calculator automatically rounds up if not selected )
  • If you have a patterned fabric decide if you want to inclue an extra pattern repeat to position the pattern on the curtain (see info button for more details and what to do with half drop pattern repeats)
  • Press Calculate

Note if you change any entries press calculate again to re-calculate.

Calculator Assumptions

  • Curtains 1.5m or shorter have a fabric double 8cm hem, lining double 6cm hem.
  • Curtains over 1.5m in length have a fabric double 10cm hem, lining double 8cm hem.
  • Calculator defaults to rounding the number of fabric widths UP to the nearest whole number. If the resultant Actual fullness ratio is too high select the option to round DOWN to the nearest whole number and re-calculate. Then check if this lower Actual fullness ratio is more suitable.
  • 5cm trimming allowance on lining cut drops
  • 10cm trimming allowance on interlining cut drops
  • 5cm trimming allowance on plain fabric cut drops (note not included for pattern fabrics as adjusted cut drops are usually longer than required)
  • Results are rounded up to nearest 10cm (0.1m)
  • Lining and interlining is assumed to be a similar width to the fabric.
  • This curtain fabric calculator is based on making curtains using the heading and hem allowances in our online tutorials. Full written explainations of the calculations the calculator is based on are given in the tutorials on this website.

    NOTE: Our goal is to make the Fabric Calculator as accurate and helpful as possible, but please double-check all results thoroughly. (see terms).

Extra Help & Comments

Sew Helpful
This is a new online calculator. Please leave any questions or feedback here. We have tested it as much as we can but that is no substitute for letting people use it, who didn't make it.
Westway Interiors
Many thanks...I worked everything out myself first, then used your calculator as my second-checker!
We got exactly the same results, so very reassuring,
Kind regards,
I am making curtains for a friend, who had already bought her fabric and lining. I used the calculator to work out the cut length I need for the patterned fabric but one thing I realised is that your calculator appears to assume the lining is the same width as the fabric. In my case the fabric is 150cm but the lining is only 140cm. Since I need two full widths to make triple-pleat curtains, I assume I will need 2+ widths of lining and therefore more metres than stated
Sew Helpful
Yes note 8 on the calculator assumptions tells you it assumes the lining and fabric are similar widths. The standard width of fabric is usually 137 to 140cm.

Whether you decide to cut the fabric down to the lining or add more lining will depend on how that will affect your fullness ratio, which will make it nearer the ideal and nearer your ideal pleat size and spacing.
Thanks for the new calculator its brilliant to check your calc against, just a quick question if i may, ive been asked to make some dress curtains (not full width, just to sit at the sides of the window) Could i ask your advices it best to work out quantities? Should i half the width and then half again for each curtain?
Many thanks in advance
Sew Helpful
We don't use any specifiic fromula. It depends on fabric the width of the window etc. If you make them too skimpy they will not look right. They need to look substantial enough that they can do the job.
This calculator is a great help, & really boosts the confidence when buying a large amount of fabric. Is there a way of saving the information once input so I can refer to it when shopping for the amount I need?
Sew Helpful
It was really just designed as a way to check your calculations for the tutorials, I'm afraid we haven't incorporated a saving/printing function.
Hi - is it possible the adjusted cut drop in this calculator is adding in one pattern repeat? Is that accurate or is the one pattern repeat added into the fabric qty calc? thank you
Sew Helpful
The adjusted cut drop is a whole number of pattern repeats so will always be longer than the cut drop or on rare occasions the same. The calculator gives you the option to add one pattern repeat to the total (NOT one pattern repeat per drop) to position the pattern on the curtains.

What figures are you putting in to think it is adding an extra pattern repeat.
pole 366
curtain length 272
fabric width 139
pattern repeat 34
type lined
number pair
heading type triple pleat
buckram depth 10
desired fulness
next 2 boxes NOT checked
I think the discrepancy in my calc vs. the calculator is the roundup of the fabric cut drop divided by the vertical repeat. I got 9.02 so didn't round up, but wonder if I should have? My answer was 306 and the calculator gave 340. THANK YOU
Sew Helpful
I think the calculator is correct in the calculation, but what we have here is the fact that the cut drop is just going into the next pattern repeat so if you make the cut drop 1cm shorter you can save a lot of fabric.

You are doing what we would do but you are not making the same calculation as the calculator which is making the strict calculation (it doesn't look at reducing allowances to save fabric). That is really for people who know how to make their own calculations and can make judgements to adjust allowances if there is a lot of fabric to be saved. 

What the calculator is doing is

Cut drop = Curtain length + Heading allowance + Hem allowance + (no trimming allowance as pattern fabric)

= 272 + 15 +20  =   307cm

The adjusted cut drop is cut drop divided by pattern repeat, then that answer rounded up to the next whole pattern repeat.

= 307 / 34 = 9.02   (strictly rounding up = 10) 

therefore adjusted cut drop = 10 x 34 = 340cm

Now in reality we would look at that and think another pattern repeat for the sake of 1cm is not worth the extra cost of all the fabric that would be needed as there are 7 drops. (7 x 34 = 2.38m of extra fabric) so we would say lets reduce the inner fold on the hem by 1cm and that will give us a cut drop of 306cm, that is exactly 9 pattern repeats so the adjusted cut drop is now

9 x 34 = 306cm

The information to make these judgements is there in the answers of the calculator, Eg  Cut drop, Adjusted Cut Drop, Heading, Hem and Trimming Allowances. It is a judgement you as the maker have to make though and is what you have done in your calculation. So in summary the calculator is strictly right, but we would have done it the same way as you and gone for an ACD of 306cm instead of 340cm to save a lot of fabric.

Note you can get caught out doing this sometimes when the actual pattern repeat when you measure it on the fabric comes out a bit longer than that given by the manufacturer.

Coming from the "older generation" afraid cm mean nothing to me it would be nice to have choice to use inches or cm - just a thought
Ben Lockspeiser
To Whom It May Concern,

I would like to purchase some fabric for making some curtains but cant work out how much fabric i need.

Area is:
W - 1.8m
L - 2.15m

The curtain rail is 1.7m

Could you please email me on

Sew Helpful
I'm afraid we do not make calculations for people.

Our website provides you with tutorials and things like this calcualtor to help you make your own calculations.
So far, the tutorial & this online calculator are proving invaluable. Thank you for your help!
Steph kyles
Extremely helpful calculator, easy to use and understand, saved on my browser for quick use.
Pamela Taylor
Purchased the video tutorial for pencil pleat curtains for a months viewing.
would have thought paying £9.95 it would allow you to view various online tutorials from your website for that time scale as I was also interested in the roman blind tutorial. Note to potential customers the price you pay is only for the item viewing.
Sew Helpful
Yes you are right it clearly states when you puchase you are buying Access to the tutorial videos for that tutorial. The information you were given is 

£9.95 28 day access to ALL Lined Pencil Pleat Tutorial videos.(max 150 streams)
Lined Pencil Pleat Curtain Tutorial 16 videos (111min)
28 day video access: £9.95 all 16 videos (max 150 streams)

The reason we chose 28 days as a period is because many people make their curtains and blinds over a period of time eg weekends, evenings when they get spare time. They usually get it done within a month. The 24hr access is really for those who want to check how to do something.

It does not say anywhere you are buying access to the whole library of videos on the website for all the tuorials.  We have never had a complaint about this before.
Anne thomas
Can you explain fabric cut drop v fabric adjusted
So do I cut it at the adjusted?
The pattern repeat is 24 cmso am I adding 24 cm to length plus hem plus header allowance
Love the site it's really helping my confidence !!
Sew Helpful
If you go to STEP 3 of one of our lined curtained curtain tutorials, it gives a full explaination of how you calculate for plain fabric and patterned fabric.

You need an adjusted cut drop with a pattern because you can't cut patterned fabric just anywhere and then expect the 2 panels to match up inline along side each other. There is a FREE video on the STEP 3 page that explains what an adjusted cut drop is and why you need one.
I put in the measurements for a curtain using double pleats with a ratio of 2. Bearing in mind that you recommend a ratio of 1.9 - 2.2 I find it strange that you came back with the fabric calculated using a ratio of 2.6 - far too much!!! How can that really be correct?
Sew Helpful
Hi Carolyn

The calculator rounds up the number of widths by default. With the number of widths you have a choice of rounding up or down to the nearest whole number when making the calculation, thus increasing or decreasing the fullness ratio.  I am currently working on the calculator adding interlined curtains, I will add the choice to round down which may result in a better fullness ratio.

A more advanced method is to actually make your curtain panel to be pleated to an exact width (rather than a number of fabric widths) to give you the exact fullness ratio you want which we sometimes do when pleating to pattern repeat, that is beyond the scope of our tutorials though. We did put that information in initially but it made the instructions very complicated and confusing trying to have 2 different options running at the same time.
For me to work out the width I need in my curtains then what is the ideal spacing size and double pleats size for a rail of 150cm and a drop of 134cms for the proportions to be right
For me to work out the width I need in my curtains then what is the ideal spacing size and double pleats size for a rail of 150cm and a drop of 134cms for the proportions to be right
Hi, the calculators and tutorials are excellent and easy to follow. I've just used the calculator for curtains but it just gives one request for pattern repeat measurement, my fabric repeat says 'v48cm h21cm' do I need both these amounts included? Thank you
Sew Helpful
It's the vertical pattern repeat that you need when calculating the fabric quantity.
Does the calculator automatically add on the 2cm on for the buckram depth ? Am I right in assuming that if you double cuffed the buckram, say 15cm buckram used, you would have to put 30cm in that box? Thank you.
Sew Helpful
The calculator is based on the making methods and calculations in the tutorials on the website. The length of buckram is the pre pleated curtain panel width plus 10cm each side. The depth of the buckram affects the amount of fabric required. On a lined curtain the fabric folds back over the buckram and is folded under the bottom. Yes the calculator adds on the 2cm.

You need to enter how deep the buckram will be on the curtain. 
Sorry, just read the info box at side !

So, if I put 15cm buckram, the calculator will calculate for 32cm ? Is this right please ?
Sew Helpful
the calculator will calculate for 32cm ? I'm sorry I dont understand the question What are you calculating when you say 32cm? The wriiten expaination of the calculation is in the curtain making tutorial.
Thank you. I understand what you mean.
I now realise I hadn't read your instructions properly and didn't add in the 1 extra pattern repeat when I calculated my fabric. I've already bought the fabric so now am in a panic. What should I do? Order more fabric? But it might be a different batch.
Sew Helpful
No you cant add it on to the bottom.

The extra pattern repeat is to allow you to place the pattern, so you should still have enough to make, you just wont be able to place the pattern where you want it on the curtain. If you have a big difference between adjusted cut drop and cut drop though you may be able to move the pattern position if you want.
Hi can you please tell me how many pleats per width equates to the actual fullness figure in the calculator. Thank you.
Sew Helpful
You need to read STEPs 2 and 9 of the curtainmaking tutorials and/or look at the pleat calculator to determine the number of pleats you need.
Madelaine Smith
Hello Sew Helpful.

I very much value your tutorials, videos and calculators and have used them all on numerous occasions.

Would it be possible to add a print facility to the calculators so they may be printed for reference during make-up.

Many thanks
Sew Helpful
We have no plans to do this but will look into it when we revamp the site.
Sue Simpson
Would you recommend more or less fullness for pleated cotton curtains with a blackout lining?
Sew Helpful
We cant say whether it is best to round up or down as it depends on how close the value will be to the original target fullness ratio.
What if you're doing sheer material, like tulle? How does the that affect the necessary amount of material for cartridge pleats?
Sew Helpful
Sheers need a bit more fabric for the sides as we make them with a double fold at the side. This fabric calculator is not for sheers.
Sophia Clarke
I want to make triple pleat interlined curtains. Does the calculator allow for returns eg 11cm, ease eg 8cm (2cm per 50cm pole) and overlap of 10cm (ie total of 29cm) ?
Using the calculator, for 2.5 fullness, this gives an actual fullness of 2.8, too much. Rounding down, gives 2.25 maybe ok but only 4 widths rather than 5. I think 4 widths will not be enough if subtracting 29cm for the above, this gives only 2.17 fullness, not enough.
Maybe best go for 2.8 fullness, 5 widths and cut down the fabric to 2.5 fullness?
Sew Helpful
We would go for the 5 widths, in our opinion the 4 wouldn’t be enough. I will need to look at how I programmed the calculator before commenting on the other part.
My calculations have come out with the exact same figure for the adjusted cut drop as cut drop. That feels a bit too good to be true. Does that sometimes happen? Curtain finished length is 278 cm; pattern repeat is 53, so exactly 6 repeats! That means there won't be a trimming allowance - is that OK?
Sew Helpful
Of course that can happen. We would probably not add the trimming allowance as you will have to add an extra 53cm to each drop. (that could add up to a lot of extra fabric). Instead we would make up carefully and if we did loose a bit to trimming, we would reduce the fabric in the hem to compensate. 
Thank you for such a prompt reply! I'll be careful....
If I round down my fullness ratio becomes 2.875 for a pair of triple pleated curtains.

Do you feel this will give the desired effect with Voyage Veraine Opal material which is to be lined?
Very many thanks.

I would ask to to you to add wave heading style to calculator. Thank you.
Sew Helpful
Thanks for the feedback, we will look at that when we write a wave heading tutorial.
Hi I am working with the frame of the window and not the track width as the room is still being renovated. How can I make allowance or how much do I add off the frame for the curtain pull back?
Sew Helpful
Generally we use an extra 20 to 30cm to each side for the pole width, depending on heading type, interlined/lined etc. If it is a really wide window with thick curtains you may need more.
Hi, Thank you for the website its tremendously helpful. The calculator matches my calculations so thats great and gives confidence that I'm working through things correctly.
Just one question I'm not sure about. I've worked through the guidance notes and I'm not sure where to account for the 10.5cm ease it recommends. Has this already been worked into the calculator or do I need to allow for it? Thank you
Sew Helpful
The fullness ratio you use effectively takes the ease and overlap into account in the figures. When calculating fabric amounts you are looking for the number of widths you use not an exact width figure at this stage. The judgement comes when you just go into another width what fullness ratio you have and whether you can round down or not. 
Sorry I should have mentioned I'm making interlined double pleat curtains.

Do you think a fullness of 2.06 is ok or should I be aiming more to 2.2? It's my first time making hand pleated curtains. Thank you
Sew Helpful
we would go for the higher fulness ratio.
I have 15 cm buckram. When I use the calculator it calculates the heading allowance as 17 cm, ie 15 + 2.
When I calculate manually I am advised to calculate heading allowance as 15 + 5
I’m confused.
I should mention that I am making lined double pencil pleat curtains
Sew Helpful
You do not use buckram to make pencil pleat curtains you use heading tape. If you click the "info" button next to the buckram value input, it tells you to put 0 in for pencil pleat curtains as the make up method is different.
I said pencil pleat but I meant double pinch pleat. When I entered my figures into the calculator, ie buckram 15cm, the heading allowance is calculated as 17 cm for the fabric.
However in the written instruction sheet the heading allowance is calculated as buckram depth plus 5cm
Sew Helpful
Thanks for spotting that Sharron, the old figure was 2cm extra, we increased it to 5cm when we reviewed the instructions recently. The calculator should now give you buckram plus 5cm.
Hi, just calculating my material requirements and I need 3 lengths. It is a patterned fabric with a repeat of 64cm. Could you tell me why I need to add 3 repeats. surele it is 2???
Many thanks
Sew Helpful
What is your cut length of fabric for each drop? that has to be converted to an adjusted cut drop or the panels will not join or meet correctly in the middle. This is explained in the tutorials.
Please assist in calculating fabric for 4.50 width in wave pleat,finish drop 2.06 and 88 runners in track
Sew Helpful
I'm sorry we don't make calculations for people. There is a calculator here on the website and pages of explaination in the tutorials on how to make the calculations with worked examples all FREE to use and read.
Kate Barrow - Bespoke Fabric Creations
Dear Sew Helpful,
Thank you so much for your curtain pleat calculator! I have a retail premises and all of the soft furnishings I make myself on the premises. I very rarely make triple pleat curtains these days, but I have had orders for a few at the minute. I find it quite confusing working out the pleat/gap ratio, and even though I know how to do this, I always double check with your online calculator, and then I am happy in the knowledge that I have it right!
Thank you so much! I have now signed up to your newsletter and look forward to reading your posts, hints and tips!
I entered a desired fullness ratio of 1.9 and the calculations returned an actual fullness ratio of 1.73. Will this be workable and look ok?
I find your tutorials very useful and will pay for the complete set when I know if pinch pleats are possible with material I have.
Sew Helpful
We would say 1.7 is the minimum you can go down to for a double pleat lined. They will look skimpy, we always go for a fuller look. We wouldn’t go that low with interlined.
How do you work out the triple pleats and how much space do we need for the space and pleats?? Please let me know as soon as you can thanks.
Sew Helpful
There is a complete tutorial on how to make a triple pleat curtain on the website. All the information can be found there.

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