• - Fabric
  • - Lining
  • - Thread
  • - Heading Tape
  • - Weights
  • - Curtain Hooks
  • Tools
  • - Sewing Machine
  • - Needles
  • - Pins
  • - Clamps
  • - Scissors
  • - Set Square
  • - Straight Edge
  • - Invisible Marker
  • - Tape Measure
  • Step 2: Calculate the Curtain Dimensions
    Printable Worksheet
    Printable Worksheet


    For a pair of curtains the Finished Curtain Width for each curtain is half the pole length plus 5cm for ease.


    To calculate the Finished Curtain Length :

    • Decide where you will be attaching the curtain hooks on the curtain heading tape (there are usually 3 positions on pencil pleat tape).
    • Choose the position that will give you a Hook to Top distance nearest your measurement in Step 1, taking into account the curtain protrudes 0.5cm above the top of the heading tape.
    • Attach a hook to your heading tape and measure from the top of the attached hook to the top of the tape.

    The calculation for the finished curtain length is then.


    When deciding how full we want our curtains to be we talk in terms of Fullness Ratio. Fullness Ratio is the ratio of the width of the curtain before pleating to its finished width when pleated or gathered. The higher the fullness ratio the more gathered and heavier the curtains will be.

    We recommend a Fullness Ratio of 2.4 to 2.5 for a pencil pleat curtain. Note that some heading tapes come with a recommended fullness ratio suggested by the tape manufacturer.

    Extra Help & Comments

    Hi, I am making triple pleated curtains with a finished drop of 145cm. Is there any rule to say what depth of buckram has to be used as long as it in proportion ? I am considering using a 15cm buckram to show 'long' pleats as the fabric I have been given is hardly enough to give a double fullness and so I think making a longer pleat would compensate for this. I hope this makes sense, thank you.
    Sew Helpful
    There are no rules we are aware of. It comes down to a design decision and if you are not sure making a mock pleat up to see what you think is best usually helps.

    We would probably go for a double pleat rather than a triple pleat if you have less than double fullness. With that length curtain we would probably go a bit shorter on the pleat length than 15cm as well. But like we say there are no rules and it comes down to personal preferences. 
    I have 15 foot wide window by 15 ft high I like three times the width how many yards will I need
    Sew Helpful
    Hi Ann unfortunately we do not make calculations for people (we would be inundated with requests). All the information you need to calculate your fabric quantities for a plain or patterned fabric is in the next step (STEP 3).
    sally mallet
    I have a curtain pole of 137 with 142 drop, I have been sold 4.90 of material. The width of the material is 1.37 cm. Is this too much material? would a width and half be too full? I measured the whole length of the pole when giving my measurements to the shop, or would one width in each curtain be sufficient?
    Sew Helpful
    They have given you enough for 1.5 widths per curtain in plain fabric which is exactly what we would have went for. We have learnt it is a false economy trying to skimp on the fabric as the curtains look no where near as good, 4.9m is what we would have ordered.

    I have a curtain pole Severn foot long, could you please advise me what width of curtains I would need for pencil pleat curtains to fit my pole?

    I've just moved to Sheltered Housing and I'm not sure how to measure for these as I previously had blinds.

    Thank you for any help you can offer, I'll be most grateful.
    Sew Helpful
    We do not make calcualtions for people but will answer questions on the written instructions.

    The way to calcualte the width of curtains is written above. For a pair of curtains each curtain when made will be half the pole length plu 5cm wide. The number of widths of fabric you will need to make each curtain is cov ered in the next step of the tutorial STEP 3.
    I have been asked to take up some pencil pleat curtains that were too long so have removed the heading tape. The curtains were hung from the third channel on the tape and the drop measurement from the eye of the ring for the pole is 217 cm , do I then add the measurement from the top of the third channel and add that and 0.5cm to get my finished drop ? I have asked so many people and have come up with lots of answers none of which are the same and am now getting worried as want to do so a nice job !!!
    Sew Helpful

    In our method you measure the hook drop (the drop measurement from the eye of the ring). Then put a hook in the row you are going to use on your heading tape and measure up to the top of the tape. Add these 2 figures together then add 0.5cm to take in to account the fabric that will be above the tape. That will give you your finished curtain length.
    I find this is helpful and am learning a lot

    I am not a professional person to make curtains, but I always make for family friends.
    I got a project to make curtains for the whole house (3 bedrooms + living and dining), which 2 of BayWindow
    Using swish aluminium corded tracks,
    I want to make all the triple and double pleats, using 15cm & 10cm buckram.
    I want to hide the track as well
    What is the best header & hooks I should buy?
    Do you think might be easier to buy the header instead of buckram for the bigger windows?
    Thanks for your help

    Sew Helpful
    We always make double pleat and triple pleat curtains using buckram (not with a heading tape). 

    There are tutorials for both these curtain heading types on the website. In the videos you will see the buckrams and hooks we use for our customers.

    If you are looking to hide the track just beware that the fabric between the pleats will push forward when the curtains are stacked back rather than fold back behind. (we show this in the video of STEP 1 of the tuorial). You may need smaller spaces between the pleats to make it look neater when stacked back (which would mean more fabric as you would have more pleats in the curtain).
    When joining the widths, do you add seam allowance? If so, how many centimetres seam allowance across the width for each seam
    Sew Helpful
    How to join fabric panels with a plain seam is shown in STEP 6 of the tutorial.

    With pencil pleat curtains you are making curtain panels up then pulling along the heading tape to reduce the panel to the required width. The fabric used in the seam when joining is inconsequntial in comparison to the widths of the 2 fabric panels joined (about 270cm). Therefore we do not need to make an allowance for it in the calculations, it is effectively included in the fullness ratio.
    Are there agents available to help at hand?
    Sew Helpful
    Im sorry I dont understand what you mean by agents. This is an area to ask questions about the tutorial we will answer but it may not be immeadiate. If you need to contact us directly  there is a contact page (link at the bottom of this page).
    Would you recommend using more than 2.5 ratio for pencil pleat curtains? I have enough fabric for around 2.7 ratio and wondered if it was worth using the extra fabric. The fabric is a slightly stiff cotton polyester mix so I wouldn't use the extra for cushions. Btw I love your tutorials! I've made 7 professional looking Roman blinds now, both lined and interlined. And although I've made plenty of curtains before, the last set I made following your instructions were the best. Best tip was not to iron the fabric which has saved me many a wobbly, stretched edge as I often use linen.
    Sew Helpful
    We would stick with 2.5 in the workshop as there is only so much you can pull the tape.
    I'm looking to make pencil pleat curtains with 5cm stand up/ frill top.
    For this am I right in thinking I take my hook drop and add 0.5cm for the tape and then the 5 cm on top
    Sew Helpful

    To calculate the finished curtain length, you need to hook drop plus measurement from hook to top of tape plus 5cm (rather than the 0.5cm)

    For your fabric quantity calculation you will need an extra 5cm length per drop as the fabric folds over at the top and comes back down to join behind the tape. 
    Helen Johnstone
    Thank you for the reply!

    So if my hook drop is 235cm and I'm using the middle pocket of a 3" pencil tape then the measurement from the middle where my hook will be to the top of the tape is 3.5cm.
    So... 235+3.5cm+5cm = finished drop

    Adding extra for cut drop for hems etc as you mentioned
    Sew Helpful

    FINISHED CURTAIN LENGTH = hook drop (235cm) + hook to top of tape (3.5cm) + 5cm above tape.


    PLAIN FABRIC CUT DROP = FINSHED CURTAIN LENGTH + Hem allowance (16 or 20cm) + Heading allowance ( 5cm normal allowance + 5cm extra for fabric down back in this case)


    PLAIN FABRIC CUT DROP = 243.5 + 20 + 10 
    I have made floor length curtains for 8 large windows. They are 3metres to 4 metres wide and 2.2m drop. 2.5 gather allowance. They look great when closed but when open the top edge droops down. I'm at a lost how to rectify... they looks awful.
    Sew Helpful
    Can you send us any photos. 

    Are you using a pole pole or a track?
    Are the curtains unable to stack back under the pole etc and getting pushed forward?

    Also what is your position of the hook on the back and how many hooks are you using and what spacing. 
    I am wanting to make curtains out of heavy wool tweed. Would it still be a 2.25 ratio for pencil pleat curtains?
    Sew Helpful
    Sarah Brown
    I have some left over fabric and am going to make some curtains. I have a drop of 150cm and have cut 3 lengths of 174cm. The 4th length is 163cm only. I really would like to use 4 lengths. What would you suggest my turnovers should be?
    Sew Helpful
    You could probably get away with 3cm at the top if you tack it down first, that would leave 10cm for your hem ( a double 5cm) or a smaller first turn followed by a longer second (but you would have to work out the position of the weights).
    Barbara Cole
    My dining room window is 244cm wide and my fabric is 136cm wide. If I use 2.5 widths in each curtain it gives me 2.7 fullness and 2 widths in each curtain gives me 2.1 fullness.

    Also another window in the same room is 142cm wide. In this window 1.5 widths in each curtain gives 2.8 fullness and 1 width in each curtain gives 1.8 fullness.

    Would you please advise me how many widths I should opt for. I am thinking that I could cut the half widths down a little so that I keep within the 2.5 fullness ratio.
    Sew Helpful
    2.1 fullness ratio will not be quite enough.

    Yes we would cut down the outer panels to make a Fullnness ratio of 2.5 of both curtains. 
    Jane Wells
    Curtain track 215
    Sight size/ cut size per drop 211
    Fabric patterned with 64 cm half drop
    Fabric width 142
    Pinch pleat heading .
    Jane wells
    Just wondered how much fabric I will require with the half drop please.
    Jane Wells
    Sew Helpful
    I'm afraid we don't make calculations for people. There is an article on the site explaining Half drop pattern repeats and how to calculate fabric quantities for them. The next STEP of the tutorial also deals with calculating fabric quantities.

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