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.
- 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).
Making your own curtains?
Find full FREE written instructions and your questions answered here in our online tutorials.
Questions & Comments
Thank you so much for the calculator. I use it a lot for my curtains. But this time I am struggling to know what to do about a horizontal pattern repeat. The fabric I am making a pair of curtains will has a vertical PR of 61.5 cms (so for a 110cm drop that is 2.5 patterns. It has a half pattern repeat). But it also has a 90cm horizontal repeat and is 137cms wide. So does that mean I can only use 90cm of the width to join it? The window is 200cm wide and so need 500+cms to do 2.5 fullness. At 90cms repeat that is 6 drops! Is that correct, or does the half pattern repeat alter things? Thanks for your wonderful website.
You join half drop pattern repeat using the full width of the fabric, but it does require a different calculation and method of cutting the drops so they match. We have written an article HERE
Which is the best tutorial to follow if I'm making wave headed curtains?
We have not made a wave tutorial as yet. The process for making a wave curtains is different so I do not think that any of the instructions are quite what you are after.
Thank you so much for providing all these useful tools and instructions. I have a question regarding half drop pattern repeats.
My chosen fabric has got a half drop pattern repeat of 59cm (the fabric width is 137cm). Shall I insert 59cm in the "pattern repeat" field on your calculator or do I need to make further adjustments? If further adjustments are required, can you please advise how I go about making them?
Attached is a picture of my measurements.
Thank you in advance and look forward to hearing from you!
You need to work out your fabric cut drop, how many widths you are using and know the full pattern repeat measurement. Then use our half drop PR fabric CALCULATOR
There is more info on half drop pattern repeats HERE
I'm making some double pinch pleat curtains for a pole of 183cm and a finished drop of 145cm and the fabric is 138cm wide with a vertical pattern repeat of 87cm. According to the fabric spec, it's a straight match so I'm assuming no adjusted cut drop? Using your calculator, it comes up at 6.1m of fabric and that each cut drop would be 176cm. However, if I multiply this by 4 (to have double width in each curtain), this is 7.04m of fabric and this doesn't account for the pattern matching. Have I done something wrong in terms of putting in my requirements as it would appear that 6.1m is if I am going to have 1.5w in each curtain. Thank you.
Looking at your figures you have rounded down the number of widths. This makes it one width per curtain (2 widths total) and gives you a fullness ratio of 1.45 . This is the wrong option and will result in far too thin, skimpy curtains. If you untick the round down number of widths box and do the standard calculation you will see the result is 3 widths (1.5 width per curtain) and a fullness ratio of 2.207 which is perfect.
If you look at the results further the fabric qty is now 8.7m, your fabric cut drop is 176cm but your adjusted cut drop is 261cm (3 pattern repeats). This is because you have just gone into the next pattern repeat. 2 pattern repeats are 174cm. For the extra 2cm needed on each drop you are having to buy an extra 2.6m of fabric. In this case we would consult a customer how they feel about reducing the fabric hem to a double 7cm hem (reducing it by 2cm) to save 2.6m fabric costs. That would give a fabric cut drop of 174cm and adjusted cut drop 174cm and quite by coincidence makes the fabric qty 6.1m. In this case we would also reduce the lining to a double 5cm hem to match.
There are a couple of risks having the adjusted cut drop exactly the same as the fabric cut drop in that you have no trimming allowance and you are relying on the actual pattern repeat on the fabric being exactly the same as the figure given. Hope that helps a bit.
Would you use blackout lining as well as interlining or would blackout replace interlining in bedroom curtains? - sorry didn't know where to post this!!
Thanks in advance
Good question but it really depends on what look you are trying to achieve, and the amount of work you want to put in. Interlining does not replace blackout and will make very little difference to the amount of light passing through the curtain. So, if you wish to achieve a darker room, then you will have to use blackout. Whether or not you wish to interline the curtains?- this is a personal design choice. If you do, then use blackout as you would lining in the tutorials. The only difference is that, when joining blackout panels, I do not press the seam open, just fold it to one side when laying it on the fabric panels.
Good luck with your project. Cindy
Have you any advice for calculating the width or curtains for completely recessed windows? They are 100 cm and 140 cm wide. There is no significant space each side for the curtains to move aside and so all the gathered material will block light - I think I need relatively thin material and less gather than recommended (I wondered about 75cm and 105 cm curtain widths) or perhaps no lining but how do I figure it out? I think I would prefer flatter gathers to blocked light but it's hard to be sure as I am making these for a relative who does not live near and I can't experiment. There is a curtain rail fitted so curtains must be appropriate.
Thanks for any suggestions
The fullness of a curtain is generally decided by the heading type. Pencil pleat requires 2.5 x fullness to look good and does not stack back as tidily as hand pleated headings whereas, if you double pleated the curtains, you could get away with less fullness and the stack back will be smaller and tidier. Possibly consider 2 x fullness hand double pleat and work out pleat and space sizes in advance, trimming down the panels to the required width.
Whether or not you line the curtains is a personal choice but I would recommend that you do.
Good luck with your project.
Your tutorials and online calculators are incredibly helpful, but I am worried about the effect a chosen fullness ratio is having on the "actual fullness ratio" in the calculator given that you say going above 2.5 might be too much and my curtains are going to be in a room that doesn't get much light and with little stackback room. I have a pole width of 150cm, Fin. Curt. Length of 193.7, Fabric width of 140 (usable) and a vertical pattern repeat of 35 and I'm going for a pencil pleat (3" header tape). On 2.5 fullness the calculator is giving an "actual fullness" of 2.733. I wonder whether this is really too much, but with my measurements, it isn't until I go down to a fullness ratio of 1.8 that the "actual" changes at all. Am I doing something wrong and/or will the actual fullness ratio of 2.733 be just way too much? I know it's down to personal choice in the end, but I don't understand why inputting various fullness ratios in the calculator doesn't alter the "actual". It's an expensive fabric and though I've made curtains before and never made a hash of it, I am worried about the end result being odd/overly full. Any advice would be very welcome.
So with a curtain pole width of 150cm, a 2.5 fullness ratio will 2.7 widths total. In my opinion, going down to 1.8 fullness ratio will make the curtains too skimpy for pencil pleat. I have learnt that pencil pleat header works best with a 2.5 fullness ratio. So you have a couple of options…
- Chop down you widths so that you have the correct fullness ratio…..using a full width and approx 45 cm from the second width on each curtain. The left over could be used for cushions.
- Choose a different header that could work with a smaller fullness ratio. You could double pleat but even then, the fullness ratio is at the bare minimum of what I would recommend.
Good luck with your project.
Hi. Firstly to say how appreciative I am of your site with all of the useful guidance and tips - just excellent. It's a long time since I have made curtains and am having a mind muddle moment.
When it comes to the calculations allowing for pattern repeat. If you have two windows in one room and using same fabric on each, do you need to allow for the pattern repeat on each pair - so allow for two pattern repeats - or one or even more? The windows are quite close, so would ideally need the pattern to be starting at the same point too at the header. Many thanks in advance.
Assuming it is a standard pattern repeat fabric and not a half drop pattern repeat.
You will need one extra pattern repeat to position the pattern for the first pair of curtains.
If you are placing the pattern in the same position on the second pair you will not need an extra pattern repeat for placing the pattern because the cut line will be in the right position when you start to cut those drops (after cutting the drops for the first curtain). This is the case even if your Adjusted Cut Drop (ACD) is different on the second pair (second pair is a different length), because the ACD is a number of whole pattern repeats, so will always start and end at the same place in the pattern.
If you are placing the pattern in a different position on the second pair you will need to add an extra pattern repeat calculating the qty for the second pair to allow for this.
Do you have calculator for inches instead of centimeters?
I'm sorry the calculator only does cm at the moment. We are metric, if you were working in inches would you expect the fractions less than one inch to be shown in decimal format eg 0.25 or fraction format eg 1/4 when entering figures and the results to be shown.
Thank you for this tutorial. I'm confused on the 'ratio' if you can help please. If a ratio is 2:5 say.... that would be two of what and five of what? I don't know what it refers to.
it is not a 2 to 5 it is 2.5. That means your flat curtain panel is 2.5 times wider than the pleated curtain . The fullness ratio effectively determines how full your curtains are going to be. There is information on this in our curtain making tutorials
Love the fact that the calculator dumps what I've already entered if I click on the info buttons. Basically, I'll never get to the end... giving up
Thanks for the feedback the page was initially designed for desktop and the info pops up when you hover over it. You dont get a hover with a touch screen it just clicks (we should have thought about that). We will remove those very shortly and add an expaliner video instead.
I need your assistance to calculate how much material I need to buy for 60 rooms (2 curtains per room)
The material is 2.8m wide and 55metre per roll.
The window sizes are 26 rooms 3x4.25 and 36 rooms is 2.7 x2.8
The hem is 25cm and fullness of 1.75
Thank you for assisting
I'm afraid we don't make calculations for people.
so from step 3 in double pleat instructions, I'm taking
pole length (300) x fullness ratio (1.9)
divide by width of fabric (137) = 4.16 widths
would that be too little for double pencil pleats? as I think the full ness ratio is below 1.9.
If i use rounding up, it goes to 5 widths which would be fullness ratio of over 2.2
Sorry for all the questions...!
We would use 5 widths. We will be adding advanced instructions shortly explaining how you cut panels to the width you need to get and exact fullness ratio which also leads on how to pleat to pattern repeat.
HI - Wonder if you can help, when I calculate the dimensions using the instructions on step 3, I get 4 widths of fabric.
when I use your online calculator i get 5 widths.
Pole Length is 300cm, I'd like double pinch pleat too.
The fabric is quite expensive, but I'm wondering if the 4 width will look too skimpy?
Thanks for any help
What figures are you using that give the 2 results?
Thank you very much Cindy for that advise. Still learning so don't really understand all of it, but have to say i'm panicking now reading it all, due to telling my friend 14 metres and being Susie Watson material not cheap. Won't be cutting it until i feel comfortable and will be doing mock ups first hehe.
Could you tell me please if i've got the calculations correct? I'm not sure if the fabric calculator includes the overlap and ease within the calculations, or if i have to add it onto the pole length? The calculations i have put in are only the pole length, so therefore,
Pole length = 240cm
Finished curtain length = 300cm
Fabric width = 135cm
Pattern repeat = 13.5cm
1 x pair
Double pleat, 2.2 ratio
No buckram, would like them interlined to the top for softer fuller look.
With one pattern repeat added and rounded up, i get it to 14 meters, but not sure if this is wrong due to me not adding the overlap and ease (20cm total) to the pole length.
Would you have to allow extra fabric for bobble trim to be sewn into the leading edge?
Would appreciate your advice.
Your question is a really interesting one as you are right on the cusp of the 5th width. Based on double pleat.
With a hand pleated heading, you can vary the size of pleats and spaces to get your required pleated width so there is flexibility on your pleat/ space ratio once you have worked out your fabric amounts based on your required fullness ratio.
As you are on the cusp of the 5th width, here are a few things to consider when deciding to go into the next width or not…
- You would not require a full half width so the pleat/spaces would be calculated first to get to the correct flat panel width and then cut down to the required size.
- As you are not using the full extra width, there will be significant wastage If the fabric is expensive, do you want the extra cost and be left with excess fabric (could make cushions?)
- The extra lining and interlining needed to go marginally into that extra width?
- The extra work involved in the extra fabric. It may not sound a lot but manoeuvring the extra fabric, lining and interlining gets tricker with every cm, particularly if you do not have a suitable space to make them on such as a worktable.
Having a quick look at your measurements, here are the options…
- To add in a trim, I create a 2 cm inverted fold along the leading edge, tack the trim in place, tack the inverted fold closed around the trim and then machine stitch in place making sure you have your 5cm side fold extending beyond the trim. Then machine stitch closed. This will take 4 cm off your panel width.
. . . . . .
- 2 widths gives you a flat panel of approx 256cm (minus your 5 cm side turns and the 4cm allowance for trim insertion)
- Your pole is 240cm, divide by 2 = 120cm (I add on 10% for ease and overlap). This now gives you a pleated width of 132cm (and leaving you 124 cm to pleat - just under the 2 x fullness)
- Taking returns and overlap of 7cm each side of curtain panel, you would end up with 12 pleats of 10.3 cm and 11 spaces of 10.7cm.
- Alternatively, 10 pleats of 12.4 cm and 9 spaces of 13.1 cm (better if using thick interliner)
- If you are unsure which would look better, I suggest making a mock up to see which you prefer but I think the 10 pleats option would be preferable.
BUT, if you wish to go into the extra width you will need to work out your pleat/ space ration in advance and cut the panel down to your required width. When deciding which is the best option, I would consider the factors mentioned above before you make your decision. To get an ideal pleat /space ratio of 12 cm, the fabric width requirement would be 2.1. Is it worth going into the extra width for such a small amount of fabric that would end up in a a lot more work, fabric, lining, interlining for the sake of either 2 cm on each pleat or minus 1 cm on each space?
In the workroom, I make this kind of decision in conjunction with my customer. With a really expensive fabric, the added increase in cost is definitely something to consider. I know that I’m a keen believer on not skimping on fabric amounts but I do not see the 10 pleat option as a compromise that would affect the finished look of the curtains. Once you get a difference in pleat space / ratio of over 1 cm, that’s when I would round up to next width.
Good luck and I hope that this fully explains the options. Send us a pic once they are made, we’d love to see!
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?
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.
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?
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.
What if you're doing sheer material, like tulle? How does the that affect the necessary amount of material for cartridge pleats?
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.
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.
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.
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
It's the vertical pattern repeat that you need when calculating the fabric quantity.
Can you explain fabric cut drop v fabric adjusted
So do I cut it at the adjusted?
The pattern repeat is 24 cm so am I adding 24 cm to length plus hem plus header allowance
Love the site it's really helping my confidence !!
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
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.
curtain length 272
fabric width 139
pattern repeat 34
heading type triple pleat
buckram depth 10
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
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
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.
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
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
What figures are you putting in to think it is adding an extra pattern repeat.
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
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.