Reed Count & Reed Width Calculator

The formula

This is the expression the tool evaluates. Every term is named underneath, with the unit it must be supplied in.

How the result is derived

Step by step, from the values you type to the figure on screen.

1. Cloth width is expanded by the weft crimp to give the width the warp must occupy in the reed.
2. The total ends are divided by the ends per dent to give the number of dents the warp needs.
3. Dents divided by reed width give the reed count in dents per inch, which is what the reed is ordered as.
4. Both setts are reported, in the reed and in the cloth, because confusing them is the classic way to order a reed that produces the wrong fabric.

What each input means

Where to read each value on the floor, the unit it must be in, and the range the tool accepts.

What the tool returns

The headline figure and every supporting value it is built from.

Worked example

Substituting

Note the two setts: 91.58 in the reed, 95.24 in the cloth. Ordering a reed against the cloth figure would leave the fabric about 4% narrow — the same 4% the weft crimp was supposed to account for.

How to use it

1. Work through the input groups in order — Cloth and Denting. The defaults are a realistic case, so you can change one value at a time and watch what moves.
2. There is no calculate button. Every figure recalculates as you type or drag, which is what makes this usable for a what-if sweep rather than a single answer.
3. Read Reed Count in the dark results panel — that is the headline figure, expressed in dents/inch.
4. Check the supporting rows underneath (Reed Width, Total Dents Used, Ends per Inch in Reed and Ends per Inch in Cloth) before acting on the headline — they are where an implausible input usually shows itself first.
5. Reset to defaults returns every field to the reference case, which is the quickest way to check whether a surprising result came from the tool or from an input you had changed earlier.

Where this is used

• Reed ordering — the count and width to specify for a new construction.
• Loom setting — checking that an available reed can weave a construction before the beam is gaited.
• Width troubleshooting — a fabric coming off narrow or wide is often a reed or denting mismatch rather than a tension problem.
• Design feasibility — total ends and denting order together decide whether the sett is realistic for the yarn.

Reading the result

Typical bands and what each one is telling you.

Assumptions and limits

• Keep ends per dent consistent across the width. Mixed denting shows as reed marks, especially on plain and fine constructions.
• Every input is bounded to the range normal practice occupies (Cloth Width 1 to 200 inch, Total Ends 1 to 50000 no. and Weft Crimp 0 to 20 %, and so on for the rest). Those bounds are guard rails against typing errors, not a claim that the formula fails one unit outside them.
• The calculation is deterministic: the same inputs always give the same result. It carries no allowance for machine condition, operator skill, ambient conditions or lot-to-lot material variation unless an input above explicitly represents one.
• Nothing is sent anywhere. The maths runs in your browser, so the numbers you type never leave the page.

Standards and further reading

• Reed count conventions differ by region: this tool works in dents per inch. The Stockport system quotes dents per two inches, so a reed described as 92s Stockport is 46 dents per inch.
• ISO 7211-3 — weft crimp measurement, the input that sets the reed width.

Questions people ask