Yarn Spinning & Preparation

Twist Multiplier to TPI & TPM Calculator

Twist multiplier is count-independent; TPI is not. Set the multiplier, read the machine setting.

Twist Specification Ring frame setting
TM
Ne

Turns per Inch

— TPI

TM x square root of the English count

Derived Twist Metrics

Turns per Metre
— TPM
Tex Twist Factor
— alpha
Surface Twist Angle
— deg
Estimated Yarn Diameter
— mm

Typical multipliers: 3.0-3.6 for weft and knitting, 3.8-4.5 for warp, above 5.0 for crepe. Twist angles beyond about 25 degrees begin to cost tenacity.

Twist Multiplier to TPI & TPM Calculator — free, with the formula and a worked example, at Textile School.