Yarn Evenness Calculator

CV is the standard deviation as a percentage of the mean: these eight cut-length masses give CV = 3.62531 %.

Measured values (masses of equal lengths, counts or strengths):

Yarn linear density (tex), optional:

With fibre fineness, gives the limit irregularity; 0 to skip.

Fibre fineness (dtex), optional:

Coefficient of variation CV =

3.62530786869986 %

Precision

Full answer, then cut to fewer decimals (not rounded):

3.62530786869986 %
3.6253078686998 %
3.625307868699 %
3.62530786869 %
3.6253078686 %
3.625307868 %
3.62530786 %
3.6253078 %
3.625307 %
3.62530 %
3.6253 %
3.625 %
3.62 %
3.6 %

Mean: 10
Standard deviation (n − 1): 0.362531
Mean deviation U %: 3 %
CV ÷ U (≈ 1.25 for a normal distribution): 1.208
Fibres in the cross-section n = yarn tex ÷ fibre tex: 133.333
Limit irregularity CVlim = 100/√n: 8.66025 %
Index of irregularity I = CV/CVlim: 0.4186

Step-by-step solution

Mean = 10, s = 0.362531
CV = s/mean × 100 = 3.62531 %
CVlim = 100/√133.333 = 8.66025 %, I = 0.4186

Yarn Evenness Formula

CV = s/x̄ × 100, CVlim = 100/√n, I = CV/CVlim

n fibres in the cross-section = yarn tex ÷ fibre tex

Worked Example

Eight cut-length masses of a 20 tex yarn spun from 1.5 dtex fibre:

Mean = 10, s = 0.362531
CV = s/mean × 100 = 3.62531 %
CVlim = 100/√133.333 = 8.66025 %, I = 0.4186

Standard deviation (n − 1): 0.362531 · Mean deviation U %: 3 % · CV ÷ U (≈ 1.25 for a normal distribution): 1.208 · Fibres in the cross-section n = yarn tex ÷ fibre tex: 133.333 · Limit irregularity CVlim = 100/√n: 8.66025 % · Index of irregularity I = CV/CVlim: 0.4186

More Textile Testing Calculators

Moisture Regain Calculator

R = (W − D)/D, M = (W − D)/W

W conditioned weight, D oven-dry weight; R = M/(1 − M)

Example: A sample weighing 110 g conditioned and 100 g oven-dry: Moisture regain R = 10 %.

Open the moisture regain calculator →
Fabric Shrinkage Calculator

s = (L₀ − L₁) ÷ L₀ × 100

area shrinkage = 1 − (1 − sₗ)(1 − s_w)

Example: A 50 × 50 cm mark that measures 48.5 × 49 cm after washing: Lengthwise (warp) shrinkage = 3 %.

Open the fabric shrinkage calculator →

Frequently asked questions

What is limit irregularity?

The CV an ideal yarn would still have from random fibre arrangement, 100/√n for n fibres in the cross-section (Martindale).

How are CV and U % related?

For a normally distributed variation CV ≈ 1.25 U %.

Sources

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.

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APA

Scientific Converters. (2026, October 15). Yarn Evenness Calculator. Retrieved October 25, 2026, from https://scientificconverters.com/calculators/yarn-evenness-calculator/

IEEE

Scientific Converters, "Yarn Evenness Calculator," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/calculators/yarn-evenness-calculator/