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 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.