Denier Calculator

The Standard Measure of Filament Fineness

Denier is the numbering system most associated with synthetic filament yarns, hosiery, and technical fabrics — a 15-denier stocking is famously sheer, while a 1000-denier nylon is thick enough for luggage and tactical gear. Like Tex, it's a direct system: a larger number means a thicker, heavier yarn, based on a fixed reference length of 9,000 meters.

The Formulas

Denier = (Weight(g) ÷ Length(m)) × 9000
Tex = Denier ÷ 9
Decitex (dtex) = Denier × 10 ÷ 9

Tex and Denier are closely related direct numbering systems that differ only by their reference length (1,000 m for Tex versus 9,000 m for Denier), which is why converting between them is a simple fixed ratio. Decitex, common in European specifications, is Denier scaled to a 10,000 m reference length.

Where This Matters

  • Hosiery and legwear — denier is the standard consumer-facing spec for tights and stockings, directly indicating sheerness versus opacity.
  • Technical and outdoor fabrics — ripstop nylon, luggage fabric, and tactical gear are commonly specified and marketed by denier count (e.g. "1000D nylon").
  • Comparing yarn across specs written in Tex or dtex — converting to a common system lets a buyer compare filament yarns quoted in different numbering conventions.

Worked Example

5 g of filament yarn measuring 500 m
SystemResult
Denier90.0
Tex10.0
Decitex (dtex)100.0

How to Use This Calculator

  1. Enter the Weight of the yarn sample in grams.
  2. Enter the Length of that same sample in meters.
  3. Select Calculate to see the result in Denier, Tex, and Decitex simultaneously.

Related Calculations

For spun yarns across all four major numbering systems, use the Yarn Count Calculator, or check a woven fabric's areal weight with the GSM Calculator.