Yarn Denier/Tex Converter

Denier is a direct system -- it measures weight per fixed length (grams per 9,000 meters), so more mass packed into that length means a heavier, thicker strand and a higher number. Ne is an indirect system inherited from cotton spinning -- it measures how many 840-yard hanks fit into a pound, so a finer yarn needs more hanks to reach that weight and gets a higher count number. The two families measure opposite things, which is the single most common source of confusion when converting between them.

Denier equals tex multiplied by exactly nine, because denier is defined per 9,000 meters of yarn and tex per 1,000 meters -- a fixed nine-to-one ratio in the length each system references, with no other conversion factor involved. A yarn measuring 100 tex is therefore 900 denier, and this calculator applies that same nine-times relationship in both directions depending on which unit you start from.

Both are indirect, length-per-weight systems where a higher number means finer yarn, but they're built on different base units. Nm is straightforwardly metric -- kilometers of yarn per kilogram -- while Ne is historically English, based on how many 840-yard hanks of cotton yarn weigh one pound, and converts to tex through the constant 590.5 rather than a round metric number. Because they come from different measurement traditions, Nm and Ne values for the same physical yarn are numerically unrelated without going through tex first.

No -- it's a rough approximation derived from the denier value using a fixed density assumption representative of a nylon-type fiber, so it will read differently for yarns made of cotton, wool, or other fibers with different densities. Treat the diameter figure as a ballpark for comparing relative thickness rather than a measurement you could substitute for a micrometer reading on the actual material.