Thread Consumption Calculator

Estimate total thread requirement per garment based on stitch classes (Lockstitch, Chainstitch, Overlock) and wastage factor.

Calculator Inputs

Length of the seam to be stitched, in meters.
Stitch type determines thread consumption multiplier factor.
Thread lost during machine threading, sewing margins, and trimming.
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Enter details on the left and click "Calculate Thread" to view results.

How this calculation works

Estimated Thread Consumption — calculated based on the selected stitch class and the stated assumptions. Thread length consumed is proportional to seam length and loop structure, plus wastage:

Thread Consumed = Seam Length * Stitch Multiplier * (1 + Wastage % / 100)

Important assumptions

  • Stitch Class: Standard garment loops (301 lock, 401 chain, 504 overlock).
  • Stitch Multiplier: Lockstitch uses 2.5x; Chainstitch uses 4.5x; 3-Thread Overlock uses 14.0x seam length.
  • Stitch Density: Assumes a standard sewing density of 10-12 Stitches Per Inch (SPI).
  • Fabric Thickness: Average knit/woven assembly of approximately 1.5mm compressed seam thickness.
  • Wastage: Default 15% allowance factors in sewing ends, thread breaks, and machine styling scrap.

Example calculation

For a 1.2-meter seam using a 3-Thread Overlock (Stitch 504) with a 15% wastage allowance:
1.2m * 14.0 (multiplier) * 1.15 (wastage) = 19.32 meters of estimated thread.

Disclaimer: Actual thread consumption may vary depending on stitch density, machine settings, seam construction, fabric type, thread type, and garment construction.

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