How to Calculate Yarn Count and Yarn Consumption

In the textile industry, understanding yarn count and yarn consumption is fundamental for fabric production, cost estimation, and quality control. Accurate calculations ensure efficient use of materials, reduce waste, and help manufacturers maintain consistency in fabric properties. This article explains what yarn count is, how it is calculated, and how to determine yarn consumption for weaving and knitting.

 

1. What is Yarn Count?

Yarn count is a numerical expression that defines the thickness or fineness of a yarn. It helps in identifying the size of yarn and is crucial in determining fabric characteristics such as texture, weight, and strength. Yarn count can be expressed in various systems depending on the type of fiber and regional preferences.

Common Yarn Count Systems:

1. Direct System (Tex, Denier, Decitex):
• Measures weight per unit length of yarn.
• Higher numbers indicate thicker yarn.
• Common units:
• Tex: grams per 1,000 meters of yarn
• Denier (D): grams per 9,000 meters of yarn
• Decitex (dtex): grams per 10,000 meters of yarn
2. Indirect System (Ne, Nm):
• Measures length per unit weight of yarn.
• Higher numbers indicate finer yarn.
• Common units:
• Ne (English Cotton Count): number of 840-yard hanks per pound of yarn
• Nm (Metric Count): number of meters per gram of yarn

Example:

• A yarn of 30 Ne is finer than 20 Ne.
• A yarn of 50 Tex is thicker than 30 Tex.

 

2. How to Calculate Yarn Count

The formula for yarn count depends on the system used.

2.1 Indirect System (Cotton Count, Ne):

Yarn Count (Ne)=Length of yarn in yardsWeight of yarn in pounds×840\text{Yarn Count (Ne)} = \frac{\text{Length of yarn in yards}}{\text{Weight of yarn in pounds} \times 840}Yarn Count (Ne)=Weight of yarn in pounds×840Length of yarn in yards​

Example:
If you have 1680 yards of yarn weighing 2 pounds:

Ne=16802×840=1Ne = \frac{1680}{2 \times 840} = 1Ne=2×8401680​=1

This means the yarn is 1 Ne (relatively coarse).

2.2 Direct System (Tex):

Tex=Weight of yarn in gramsLength of yarn in meters×1000\text{Tex} = \frac{\text{Weight of yarn in grams}}{\text{Length of yarn in meters}} \times 1000Tex=Length of yarn in metersWeight of yarn in grams​×1000

Example:
If 1,000 meters of yarn weighs 50 grams:

Tex=501000×1000=50 TexTex = \frac{50}{1000} \times 1000 = 50 \, \text{Tex}Tex=100050​×1000=50Tex

2.3 Denier:

Denier=Weight of yarn in grams×9000Length of yarn in meters\text{Denier} = \frac{\text{Weight of yarn in grams} \times 9000}{\text{Length of yarn in meters}}Denier=Length of yarn in metersWeight of yarn in grams×9000​

Example:
If 1,000 meters of yarn weighs 50 grams:

Denier=50×90001000=450 DenierDenier = \frac{50 \times 9000}{1000} = 450 \, \text{Denier}Denier=100050×9000​=450Denier

 

3. What is Yarn Consumption?

Yarn consumption refers to the amount of yarn required to produce a specific quantity of fabric. Knowing yarn consumption is essential for planning, budgeting, and inventory management in textile manufacturing. Yarn consumption depends on several factors:

• Fabric type (woven, knitted, non-woven)
• Yarn count and twist
• Fabric density (ends per inch and picks per inch for woven fabrics)
• Fabric width and length
• Shrinkage allowance

 

4. How to Calculate Yarn Consumption

4.1 Yarn Consumption for Woven Fabrics

The general formula is:

Yarn Consumption (kg)=Fabric Length (m) × Fabric Width (m) × GSMYarn Count Factor × 1000\text{Yarn Consumption (kg)} = \frac{\text{Fabric Length (m) × Fabric Width (m) × GSM}}{\text{Yarn Count Factor × 1000}}Yarn Consumption (kg)=Yarn Count Factor × 1000Fabric Length (m) × Fabric Width (m) × GSM​

Where:

• GSM = Grams per square meter of fabric
• Yarn Count Factor depends on the yarn count system used (Ne, Tex, Denier)

Detailed Method:

1. Determine the fabric area:

Fabric Area (m²)=Length (m)×Width (m)\text{Fabric Area (m²)} = \text{Length (m)} × \text{Width (m)}Fabric Area (m²)=Length (m)×Width (m)

2. Calculate total fabric weight:

Weight (g)=Fabric Area (m²)×GSM\text{Weight (g)} = \text{Fabric Area (m²)} × \text{GSM}Weight (g)=Fabric Area (m²)×GSM

3. Convert weight into yarn requirement:

• For cotton yarn in Ne:

Yarn Required (kg)=Weight (g)1.69×Ne\text{Yarn Required (kg)} = \frac{\text{Weight (g)}}{1.69 \times \text{Ne}}Yarn Required (kg)=1.69×NeWeight (g)​

(1.69 is a constant used for cotton yarn in standard calculations; it may vary based on the formula used in the textile mill.)

 

4.2 Yarn Consumption for Knitted Fabrics

Knitted fabrics generally use a similar approach, but the calculation also accounts for:

• Loop length
• Stitch density
• Fabric width
• Shrinkage

Example Formula for Knitting:

Yarn Consumption (kg)=Fabric Weight (g)×Width FactorYarn Count Factor\text{Yarn Consumption (kg)} = \frac{\text{Fabric Weight (g)} × \text{Width Factor}}{\text{Yarn Count Factor}}Yarn Consumption (kg)=Yarn Count FactorFabric Weight (g)×Width Factor​

Textile software often simplifies this calculation by integrating stitch and loop density data.

 

5. Factors Affecting Yarn Consumption

1. Fabric Type: Heavy denim uses more yarn than lightweight T-shirts.
2. Yarn Fineness: Coarser yarn consumes more weight per unit length.
3. Fabric Density: Higher thread count fabrics require more yarn.
4. Fabric Width: Wider fabrics naturally consume more yarn.
5. Shrinkage Allowance: Additional yarn is needed to account for shrinkage during finishing.

 

6. Practical Example

Problem:
Calculate the yarn consumption for 100 meters of fabric with 1.5 m width, GSM 200, using 30 Ne cotton yarn.

Solution:

1. Fabric area = 100 × 1.5 = 150 m²
2. Fabric weight = 150 × 200 = 30,000 g = 30 kg
3. Yarn consumption (approx.):

Yarn Required=301.69×30≈0.593 kg\text{Yarn Required} = \frac{30}{1.69 × 30} \approx 0.593 \, \text{kg}Yarn Required=1.69×3030​≈0.593kg

(Note: Constants may vary by mill; this is a standard estimation.)

 

7. Conclusion

Calculating yarn count and yarn consumption is crucial in textile manufacturing for accurate fabric production, cost management, and inventory planning.

• Yarn count defines the fineness or thickness of yarn and can be calculated using direct (Tex, Denier) or indirect (Ne, Nm) systems.
• Yarn consumption estimates the amount of yarn needed for a specific fabric, depending on GSM, fabric width, length, density, and yarn count.

Understanding these calculations helps textile professionals optimize material usage, reduce waste, and ensure consistent fabric quality, making it a vital skill for mill managers, merchandisers, and textile engineers.