Yarn Twist Calculator
The twist multiplier normalises twist for yarn fineness, TM = TPI/√Ne: a 20s yarn with 16.1 TPI has TM = 3.6001, a typical hosiery twist.
3.60006944377466
Full answer, then cut to fewer decimals (not rounded):
- 3.60006944377466
- 3.6000694437746
- 3.600069443774
- 3.60006944377
- 3.6000694437
- 3.600069443
- 3.60006944
- 3.6000694
- 3.600069
- 3.60006
- 3.6000
- 3.600
- 3.60
- 3.6
- Twist multiplier TM = TPI/√Ne
- 3.6001
- Turns per inch TPI
- 16.1
- Turns per metre TPM
- 633.858
- Metric twist factor αm = TPM/√Nm
- 108.92
- Tex twist factor αtex = TPM × √tex
- 3444.3
- Count in Ne
- 20
- Count in tex
- 29.5271
Step-by-step solution
- Ne = 20, so √Ne = 4.47214
- TPI = 16.1
- TM = TPI ÷ √Ne = 16.1 ÷ 4.47214 = 3.6001
Yarn Twist Formula
TM = TPI ÷ √Ne
αm = TPM ÷ √Nm, αtex = TPM × √tex; 1 TPI = 39.37 TPM
Worked Example
A 20s Ne cotton yarn with 16.1 turns per inch:
- Ne = 20, so √Ne = 4.47214
- TPI = 16.1
- TM = TPI ÷ √Ne = 16.1 ÷ 4.47214 = 3.6001
Turns per inch TPI: 16.1 · Turns per metre TPM: 633.858 · Metric twist factor αm = TPM/√Nm: 108.92 · Tex twist factor αtex = TPM × √tex: 3444.3 · Count in Ne: 20 · Count in tex: 29.5271
More Yarn Manufacture Calculators
-
Draft Calculator
Draft = N_out × doublings ÷ N_in
indirect counts; mechanical draft = delivery ÷ feed surface speed; actual = mechanical ÷ (1 − waste)
Example: A 0.12 hank sliver drafted to a 1 hank roving with no doubling: Actual draft = 8.33333.
-
Spinning Production Calculator
kg/h = speed (m/min) × 60 × ktex × η ÷ 1000
ring frame: delivery speed = spindle rpm ÷ TPM
Example: A card delivering 5 ktex sliver at 150 m/min and 90 % efficiency: Production = 40.5 kg/h.
-
Yarn Diameter Calculator
d = √[4 × tex × 10⁻⁶ ÷ (π ρ φ)]
ρ fibre density, φ packing fraction; Peirce cotton d (in) = 1/(28√Ne)
Example: A 20s cotton yarn (ρ = 1.52 g/cm³, φ = 0.6): Yarn diameter d = 0.203034 mm.
Frequently asked questions
What twist multiplier is used for warp and hosiery yarns?
Roughly 4.0–4.5 for ring-spun warp yarns, 3.6–3.8 for weft and 3.2–3.5 for soft hosiery yarns on the cotton system.
How do I convert TM to the metric twist factor?
αm = TPM/√Nm ≈ 30.25 × TM, since TPM = 39.37 TPI and Nm = 1.6934 Ne.
Sources
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Yarn Twist Calculator. Retrieved October 25, 2026, from https://scientificconverters.com/calculators/yarn-twist-calculator/
IEEE
Scientific Converters, "Yarn Twist Calculator," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/calculators/yarn-twist-calculator/