Lycra Percentage Calculator

Lycra Percentage Calculator

Find the Lycra (elastane) percentage in a circular knitted fabric from the machine setting, yarn count, stitch length and Lycra consumption.
Default values are typical for a 34s cotton single jersey with 20 denier Lycra, so you can press Calculate right away.

Machine Diameter (inch) Diameter of the circular knitting machine

Machine Gauge (needles per inch) Common gauges: 18, 20, 24, 28

Yarn Count (Ne, for example 34 for 34/s) English cotton count of the base yarn

Machine S.L (mm) Stitch length of the base yarn in mm

Lycra Denier (D) Common Lycra deniers: 20D, 30D, 40D

Lycra C.M (cm per machine revolution) Length of Lycra consumed in one revolution

Calculate Refresh

Lycra Percentage Formula

In a plated single jersey fabric, the weight of each material in a stitch is its length multiplied by its linear density. The Lycra percentage is the Lycra share of the total weight.

Total needles = Machine Diameter x Machine Gauge x 3.1416
Lycra stitch length (mm) = (Lycra C.M x 10) / Total needles
Base yarn denier = 5314.9 / Yarn count (Ne)
Lycra weight = Lycra stitch length x Lycra denier
Yarn weight = Machine S.L x Base yarn denier
Lycra % = Lycra weight / (Lycra weight + Yarn weight) x 100

Lycra C.M is the length of Lycra in cm consumed in one machine revolution. Multiplying by 10 converts it to mm, and dividing by the needle count gives the Lycra length in each stitch.
To check the needle count for other machine sizes, use the circular knitting needle number calculator. To get the base yarn denier from the Ne count, use the Ne to denier calculator.

How to Calculate Lycra Percentage in Fabric

1. Enter the machine diameter and gauge to get the total number of needles.
2. Enter the base yarn count in Ne and the machine stitch length in mm.
3. Enter the Lycra denier and the Lycra consumption in cm per machine revolution.
4. Click Calculate to see the Lycra percentage and the base yarn percentage.
5. Click Refresh to return to the default values.

Worked Example

Machine 30 inch diameter, 28 gauge, 34s Ne cotton, stitch length 2.9 mm, 20D Lycra and Lycra C.M of 250 cm per revolution.
Total needles = 30 x 28 x 3.1416 = 2,638.94
Lycra stitch length = (250 x 10) / 2,638.94 = 0.947 mm
Base yarn denier = 5314.9 / 34 = 156.32 D
Lycra weight = 0.947 x 20 = 18.95 and yarn weight = 2.9 x 156.32 = 453.33
Lycra % = 18.95 / (18.95 + 453.33) x 100 = 4.01%

Other Lycra Percentage Shortcuts for Yarn

For elastic core spun yarn, where Lycra is drafted before it is covered, these shortcut formulas are used.
Lycra % = [(Lycra denier / Lycra draft) / Resultant yarn denier] x 100
Lycra % = [(Yarn count Ne x Lycra denier) / (5314.9 x Lycra draft)] x 100

Lycra Percentage Chart

The chart shows how the Lycra percentage changes single jersey properties at a constant loop length of 2.5 mm.

Lycra %	Wales/cm	Courses/cm	Fabric Weight (g/m2)	Width (cm)	Bursting Strength (kgf)
0% (100% cotton)	14.5	30	125	92	7.5
4.3%	14.0	32	130	91	8.0
5.0%	13.8	33	132	90	8.5
5.7%	13.5	34	135	89	9.0

More Lycra gives a tighter structure with fewer wales and more courses per cm, a heavier fabric, a narrower width and higher bursting strength.

Lycra Percentage Formula

The Lycra percentage is the weight of Lycra divided by the total weight of Lycra and base yarn, multiplied by 100.
Lycra % = Lycra weight / (Lycra weight + Yarn weight) x 100

How to Calculate Lycra Percentage in Yarn

In elastic core spun yarn, divide the Lycra denier by the Lycra draft, then divide by the resultant yarn denier and multiply by 100.
Example: 70D Lycra, draft 3.25 and 50 Ne yarn (5314.9 / 50 = 106.30 D) gives (70 / 3.25) / 106.30 x 100 = 20.26%.

How to Calculate Lycra Percentage in Knitted Fabric

Find the total needles from machine diameter and gauge, convert the Lycra consumption per revolution into Lycra stitch length, then compare the Lycra weight with the base yarn weight in one stitch.
The calculator above does these steps for you, and the default values give 4.01%.

How to Calculate Lycra Percentage in Fabric

Fabric composition is declared by weight, so the Lycra percentage is the Lycra weight divided by the total fabric weight.
For knitted fabric use the stitch based method above, and confirm the declared value with a fibre content test when an exact figure is required.

Frequently Asked Questions

What Lycra percentage is normal in knit fabric?
Single jersey and rib fabrics commonly contain about 2 to 6 percent Lycra, depending on the required stretch and recovery.

What does Lycra C.M mean?
It is the length of Lycra, in cm, consumed by the machine in one revolution. Measure it on the machine and enter the value in the calculator.

Why is the Lycra percentage calculated by weight?
Fabric composition labels are declared by weight, so the calculation compares the weight of Lycra with the weight of the base yarn in each stitch.

Can I use tex or denier for the base yarn?
This calculator takes the base yarn in Ne. To convert, Ne = 5314.9 / denier, or use the denier to Ne calculator.

Lycra percentage formula

The formula for calculating Lycra percentage is derived from key parameters in textile manufacturing. By inputting machine diameter, machine gauge, yarn count, machine S.L, and Lycra C.M into the Lycra Percentage Calculator, you can quickly determine the percentage of Lycra in your fabric.

Lycra Percentage Calculation

Parameter	Formula	Explanation
Needle Count	Needle Count = Machine Diameter × Machine Gauge × π	Calculates the total number of needles in the knitting machine.
Lycra Stitch Length (LycraSL)	LycraSL = (Lycra C.M × 10) / Needle Count	Determines the length of Lycra yarn per stitch.
Lycra Count	Lycra Count = 5315 / Lycra Denier	Converts Lycra denier to count for calculations.
Lycra Percentage	Lycra Percentage = (LycraSL / Lycra Count) × 100	Calculates the percentage of Lycra in the fabric.

Other lycra percentage in yarn shortcuts you can use:

1. Lycra Percentage = [(Lycra denier/ lycra draft)/ Resultant yarn denier] × 100%
2. Lycra Percentage = [(Lycra denier/ lycra draft)/5314.9/ Resultant yarn Ne] × 100%
3. Lycra Percentage = [(yarn count (Ne) × lycra denier)/(5314.9 × lycra draft)] × 100℅.

Lycra Percentage Chart

Here is the Lycra percentage chart about the impact on fabric properties.

Lycra %	Loop Length (mm)	Wales/cm	Courses/cm	Fabric Weight (g/m²)	Thickness (mm)	Width (cm)	Porosity	Bursting Strength (kgf)	Elongation (cm at 200 cN)
0% (100% Cotton)	2.5	14.5	30	125	0.5	92	0.82	7.5	1.5
4.3%	2.5	14.0	32	130	0.52	91	0.78	8.0	2.0
5.0%	2.5	13.8	33	132	0.53	90	0.76	8.5	2.3
5.7%	2.5	13.5	34	135	0.54	89	0.74	9.0	2.5

Notes:

Loop Length: Maintained at 2.5 mm for consistency.

Wales/cm & Courses/cm: Slight decrease in wales/cm and increase in courses/cm with higher Lycra content, indicating tighter fabric structure.

Fabric Weight: Increases with higher Lycra percentages due to denser fabric formation.

Thickness: Slight increase observed, contributing to a more substantial fabric feel.

Width: Decreases as Lycra content increases, attributed to the elastic recovery of Lycra pulling the fabric together.

Porosity: Reduces with higher Lycra content, leading to less air permeability.

Bursting Strength: Enhances with increased Lycra, offering better resistance to pressure.

Elongation: Improves significantly, providing greater stretchability.

Lycra Percentage Calculation

1. Needle Count Calculation

The total number of needles in the knitting machine is calculated as:

Needle Count =Machine Diameter×Machine Gauge×π

• Machine Diameter: Diameter of the circular knitting machine (in inches).
• Machine Gauge: Number of needles per inch in the machine.
• π (Pi) = 3.1416

This gives the total number of needles available for knitting.

2. Lycra Stitch Length (LycraSL) Calculation

The Lycra stitch length per loop is calculated as:

• Lycra C.M: Lycra consumption per centimeter.
• Needle Count: Total needles in the machine (from Step 1).
• 10: Conversion factor (since Lycra C.M is given per centimeter, and we need per 10 cm).

This determines how much Lycra is consumed per stitch.

3. Lycra Count Calculation

Lycra count is usually calculated based on Lycra yarn count denier (D). For example, if 20 Denier Lycra is used, the Lycra count is:

This represents the count of Lycra in textile calculations.

4. Lycra Percentage Calculation

Finally, the Lycra percentage in fabric is given by:

This formula determines how much Lycra is present in the fabric as a percentage of the total material.

Example Calculation

Let’s assume the following values:

Machine Diameter = 30 inches

Machine Gauge = 28

Lycra C.M = 2.5

Lycra Denier = 20

Step 1: Needle Calculation

Needle Count=30×28×3.1416=2638.94Needle Count=30×28×3.1416=2638.94

Step 2: Lycra Stitch Length Calculation

LycraSL=2.5×102638.94=252638.94=0.00947LycraSL=2638.942.5×10​=2638.9425​=0.00947

Step 3: Lycra Count Calculation

Lycra Count=531520=265.75Lycra Count=205315​=265.75

Step 4: Lycra Percentage Calculation

Lycra Percentage=(0.00947265.75)×100=0.00356%Lycra Percentage=(265.750.00947​)×100=0.00356%

Thus, the Lycra percentage in the fabric is approximately 0.00356%.

How to calculate lycra percentage in yarn?

1. Machine Details:
   • Enter the knitting machine diameter and machine gauge used in your textile production process.
2. Yarn Count:
   • Input the yarn count, a crucial factor in determining the composition of the fabric.
3. Machine S.L and Lycra C.M:
   • Specify the machine S.L (Stitch Length) and Lycra C.M (Centimeters) used in your production.
4. Click “Calculate Lycra Percentage”:
   1. The Lycra Percentage Calculator will instantly provide you with the precise percentage of Lycra in your fabric.

Application of Lycra Percentage

The Lycra Percentage Calculator is a valuable tool for textile manufacturers and designers. It allows for accurate planning and optimization of fabric compositions, ensuring the desired level of stretch and comfort in the final product. Whether you are crafting sportswear, swimwear, or any stretchable garment, knowing the Lycra percentage is vital for achieving the desired performance and aesthetic qualities.

In conclusion, the Lycra Percentage Calculator simplifies the process of determining Lycra content in fabrics, offering convenience and accuracy in textile production. Explore its potential applications and elevate your fabric design and manufacturing processes.