Thread Consumption Calculator

Work out thread consumption instantly with clear inputs, formula shown and shareable results.

About Thread Consumption Calculator

Thread consumption is a multiple of seam length that depends on stitch type: about 2.5-3 times for lockstitch, 4 for chainstitch, 12-16 for three-thread overlock and 18-22 for five-thread safety stitch. A wastage allowance of 10-20% covers thread trimmed at seam ends, re-threading and cone tails.

Formula

Thread consumption

Thread = seam length x stitch ratio x (1 + wastage %)

Worked example

With the default values below, Thread Consumption Calculator returns Thread Required of 25.760. Change any input above and every figure here is recalculated in your browser.

Inputs used

Total Seam Lengthminimum 0.001 m: 8 m
Stitch Typeone of Lockstitch (301), Chainstitch (401), Overlock 3-thread (504), Overlock 5-thread (516): Lockstitch (301)
Thread Wastage Allowanceaccepts 0–60 %: 15 %
Thread Costminimum 0 per metre: 0.35 per metre

Results

Thread Required: 25.760
Thread To Seam Ratio: 2.80
Thread Before Wastage: 22.400
Thread Cost: $9.016

Step by step

1Values used
2Thread consumption
3Thread Required= 25.760
4Thread To Seam Ratio= 2.80
5Thread Before Wastage= 22.400
6Thread Cost= 9.016

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

Why does overlock use so much thread?

The loopers wrap thread around the fabric edge, so several metres of thread are laid for every metre of seam. Wider bite and higher stitch density increase it further.

Does fabric thickness matter?

Yes. Thicker fabric increases the thread needed per stitch to traverse the material, so heavyweight denim consumes noticeably more than the same seam length in shirting.