No announcement yet.

Calculating Plain & Patterned Fabric Quantities..

  • Filter
  • Time
  • Show
Clear All
new posts

  • Calculating Plain & Patterned Fabric Quantities..

    Calculating fabric quantities – Plain fabrics

    For the purpose of this example we have based the calculations on a pair of 3” pencil pleat curtains, 2.5 x the track width, the fabric width is 137cm.

    The track is 200cm wide and the finished drop of the curtains is 250cm. Hem and top folding allowances are 30cm. (You can adjust the hem and top turnings accordingly)

    1. Calculate the total number of fabric widths required: Fabrics widths also known as drops.

    Track width 200cm x 2.5 fullness = 500cm total width required. We require two curtains so divide the total width by 2.

    500cm’s divide 2 = 250cm; divide this figure by the fabric width which in this case is 137cm to give you the number of drops required per curtain.

    250cm divided by 137cm = 1.82 widths of fabric required – Round up to 2 whole widths per curtain, giving you a total of 4 drops required.

    NB. within this required width you will need to allow for your seam allowances to join the fabrics, and a minimum of 5cm each side of both curtains for the vertical side turnings.

    2. We now need to establish the total number of metres required to make the curtains. To do this we need to take the finished length required, 250cm plus the hem and top turning allowances as mentioned above to get the cut drop.

    Finished drop 250cm + the hem and top turnings 30cm = 280cm cut drop.

    The cut drop figure is the length that you need to cut each drop to – You require a total of 4 drops for this set of curtains, 2 widths of fabric in each curtain.

    280cm cut drop x 4 widths = 1120cm divide this by 100cm’s (1 metre) 11.2 metres of fabric required, round this figure up and buy 12 metres.

    Establishing fabric quantities for patterned fabrics

    NB. The pattern repeat is where the pattern on the fabric repeats and should be measured from where the pattern starts and ends. When cutting off the roll, count the pattern repeats down the fabric to establish the correct cut length. The picture below explains the pattern repeat, each "P" signifies a pattern repeat.


    In order to establish the correct amount of patterned fabric required we first need to calculate the pattern repeat. We'll use the cut drop as 280cm as explained above for this example also and the pattern repeat for the purpose of this example is 27.5cm.

    We need to calculate how many times the pattern repeats within the cut drop, this is done by dividing the cut drop by the pattern repeat.

    280cm cut drop divided by 27.5cm pattern repeat = 10.18. Round this figure up to the nearest whole number giving a total of 11 pattern repeats per cut drop. We will add 1 extra full pattern repeat to the overall figure at the end.

    Our pattern repeats 11 times within our cut drop - we now need to multiply the amount of repeats by the actual repeat, this will give us our new cut drop for patterned fabric.

    11 x 27.5cm = 302.50cm. 302.50cm is the required length of fabric per drop, we have 4 drops as above, and we will add one extra pattern repeat to the overall figure.

    4 drops x 302.50cm = 1210cm + 27.5cm (extra pattern repeat) = 1237.5cm, divide this by 100cm (1 metre) and round up to the nearest metre. Buy 13 metres of fabric.

    Calculating Half Drops - Click Here
    MyDecozo Admin