Sewing thread plays a very important part in apparel manufacturing. You have to calculate sewing thread consumption for costing as well as for the procurement of thread before starting the apparel production. It is really important to calculate correct thread requirement to avoid any excess/shortage during the order execution.

There are two common methods for calculating the thread consumption.

In this method you need to measure the seam length and then the thread to be pulled out of this length. You can use the amount pulled out of this specified length to calculate the ratio of thread consumed in the entire seam.

Dividing the amount of thread by the seam length, you get the ratio of thread consumed. Multiply this factor times the total length of seam, you will get the total thread consumed for that seam.

The below example shows the total thread consumed for one type of stitch in a garment (stitch class 401 = 2-Thread Chain stitch) . By following the similar procedure, you can calculate the thread consumed for different stitching operations in a garment.

Example:

• Length of seam = 100 cm (1 metre)
• Stitch class 401 = 2-Thread Chain stitch
• Length of seam for which thread is removed = 15 cm
• Needle thread removed = 19.5 cm
• 19.5/15 = 1.3
• Looper thread removed = 62.0 cm
• 62.0/15 = 4.1
• Total Needle thread = 100 cm x 1.3 = 130 cm
• Total Looper thread = 100 cm x 4.1 = 410 cm
• Total thread consumed = 130 + 410 = 540 cm
• Add 15% wastage* = 540 cm x 1.15 = 621 cm

*Generally, 10% to 15% wastage of thread is added to the consumption . This wastage occurs due to shop-floor conditions like machine running, thread breakage, repairs, etc.