dtex and denier describe yarn, not cloth weight. Confirm the unit with the mill before writing it on a PO.
Dtex to Denier: Convert Yarn Fineness Without Guessing
Denier is grams per 9,000 meters of yarn and dtex is grams per 10,000 meters, so denier equals dtex times 0.9. The two units describe the same yarn fineness on different scales.
Dtex to denier is a fixed conversion, not a judgement call. Denier (D) is grams per 9,000 meters of yarn; dtex is grams per 10,000 meters. The only difference is the reference length:
Denier (D) = dtex × 0.9
dtex = Denier (D) ÷ 0.9
So 150 dtex = 135 D, and 150 D = 167 dtex. Both describe the same yarn on different scales.
The trap worth stating plainly: "150" on a purchase order means nothing until the unit is named. 150 dtex and 150 D are different yarns, and the difference is small enough to pass unnoticed on a sample and fail a bulk order.
Full conversion table
Common polyester filament counts, both directions:
| Denier (D) | dtex | Typical use |
|---|---|---|
| 75 D | 83 dtex | Fine bed linen, microfiber-hand fabrics |
| 100 D | 111 dtex | Fine sheers, soft bedding |
| 150 D | 167 dtex | Standard polyester home-textile warp and weft |
| 200 D | 222 dtex | Mid-weight drapery |
| 210 D | 233 dtex | Common in continental specs |
| 300 D | 333 dtex | Curtains, heavier bedding |
| 400 D | 444 dtex | Upholstery base cloth |
| 600 D | 667 dtex | Technical and heavy furnishing |
| 1000 D | 1111 dtex | Coarse industrial and reinforcing yarn |
Read the table in either direction. If a supplier quotes 111 dtex and the buyer needs 100 D, that is the same yarn — and confirming it costs one message instead of one sample run.
Where tex fits
The same family, different reference lengths:
| Unit | Grams per | Used for |
|---|---|---|
| tex | 1,000 m | Coarse and technical yarns, engineering textiles |
| dtex | 10,000 m | Standard filament fineness, the continental convention |
| denier | 9,000 m | The North American convention, and the unit on most apparel and home-textile labels |
1 dtex = 10 tex, and 1 denier = 0.9 dtex.
Writing it on a purchase order
Three numbers belong on the same line, and they answer different questions:
| Field | Question it answers | Unit |
|---|---|---|
| Yarn denier / dtex | How fine is the strand? | D or dtex |
| GSM | How heavy is one square meter of cloth? | g/m² |
| Width | How wide is the finished roll? | cm |
Yarn fineness and cloth weight move independently: a fine yarn in a dense sett can produce a heavier cloth than a coarser yarn in an open one. That is why a PO that carries only "150D fabric" is under-specified — and why "20D fabric" is still a yarn number, not a cloth weight.
Which unit should you write first?
Match the counterparty rather than imposing yours:
- European and most international mills quote dtex — so if you are buying across regions, write both:
150D / 167 dtex. - North American home-textile and apparel buying uses denier as the default label.
- When a spec arrives as dtex only, converting before you reply saves a clarification round-trip — and confirms both sides are looking at the same yarn.
Read next: the denier glossary page for what the number does and does not tell you, polyester yarn denier guide for how yarn choice moves the finished cloth, and GSM for the other half of the specification. To convert a number right now, use the denier to dtex converter.
Common questions
How do you convert dtex to denier?
- Multiply the dtex by 0.9. The factor is simply the ratio between the two reference lengths: denier is grams per 9,000 meters and dtex is grams per 10,000 meters, so 9,000 / 10,000 = 0.9. 150 dtex is 135 D, and 150 D is 167 dtex.
Is 150 denier the same as 150 dtex?
- No, and this is the single most common mistake in textile RFQs. 150 dtex is 135 denier, a slightly finer yarn. If a PO says 150/150 without units, confirm which unit was meant before the yarn is ordered — the two describe different yarn.
Why does the unit matter on a purchase order?
- Because denier and dtex are both yarn fineness while GSM is cloth weight, and a quote that mixes them is not a comparable quote. Naming the unit, the yarn count and the fabric GSM on the same document is what makes two mills' prices comparable.
Is dtex used outside Europe?
- Dtex is the continental and international convention for filament yarn fineness, while denier dominates in North American apparel and home-textile buying. Export specs frequently carry both, so a European mill quote and a US buyer using the same yarn should be able to convert between them without re-sampling.
What denier do I need for bedding fabric?
- Most polyester home-textile programs sit between 75D and 150D for warp and weft, with heavier constructions for curtains and upholstery. But the yarn denier alone does not fix the cloth: sett, weave and finish decide GSM, so specify all three rather than substituting one for another.
Related Terms
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