# Weft Yarn Requirement Calculator

> Calculate the weft yarn weight for a woven fabric from picks per inch, reed width, fabric length, wastage and the weft count in Ne, tex or denier.

Category: Textile & apparel · Applies to: Worldwide · Last updated: 2026-10-29
Interactive calculator: https://calculators.geekmidst.com/calculators/weft-yarn-requirement-calculator

Every pick runs the full reed width, so weft length = picks per metre × fabric length × reed width. Multiply by the yarn’s weight per metre.

Also called: Weft weight calculator, Weft consumption calculator.

## Inputs
- Picks per inch (PPI) (default 80)
- Reed width (unit in; default 63)
- Fabric length (unit m; default 1000)
- Wastage (unit %; default 3; optional)
- Weft count (default 30)
- Count system (options: Ne (English cotton count), Tex (g per 1000 m), Denier (g per 9000 m), Nm (metric count), dtex (g per 10 000 m); default ne)

## Results
- Weft yarn needed
- Total picks
- Weft yarn needed
- Total weft yarn length
- Weft weight per metre of fabric

## Formula

```
Picks = PPI × 39.37 × Length (m);  Weft kg = Picks × Reed width (m) × (1 + Wastage%) × Tex ÷ 1,000,000
```

Where:
- PPI: picks per inch in the fabric
- Reed width: width of the warp in the reed (1 in = 0.0254 m)
- Tex: grams per 1000 m (Ne converts as 590.54 ÷ Ne)

## Worked example
1. Picks = 80 per inch ÷ 0.0254 m × 1,000 m = 3,149,606.
2. Each pick is 63 in = 1.6002 m long, so weft length = 3,149,606 × 1.6002 × 1.03 = 5,191,200 m.
3. Ne 30 = 590.54 ÷ 30 = 19.685 tex, so weight = 5,191,200 × 19.685 ÷ 1,000,000 = 102.19 kg.

**Result:** 1,000 m of fabric at 80 PPI on a 63-inch reed in Ne 30 weft needs about 102.2 kg of weft including 3% wastage.

## What the result means

Add warp and weft weights for the total yarn order; their sum divided by fabric area is a good cross-check against the fabric GSM.

## Assumptions and limits
- Weft crimp is covered by using the reed width rather than the fabric width.
- Wastage is a percentage of the weft length.
- Shuttleless looms with tucked-in or leno selvedges add a little extra weft per pick that is not modelled separately.

## Questions

### Why use reed width instead of fabric width?

The weft is inserted across the reed and then the fabric narrows as the weft crimps, so reed width already includes weft crimp.

### Can I use denier for the weft?

Yes. Choose denier as the count system; it is converted to tex as denier ÷ 9.

## Related calculators
- [Warp Yarn Requirement Calculator](https://calculators.geekmidst.com/calculators/warp-yarn-requirement-calculator)
- [Yarn Count Ne to Tex Converter](https://calculators.geekmidst.com/calculators/yarn-count-ne-to-tex-calculator)
- [Yarn Count Denier to Tex Converter](https://calculators.geekmidst.com/calculators/yarn-count-denier-to-tex-calculator)
- [Fabric GSM Calculator](https://calculators.geekmidst.com/calculators/fabric-gsm-calculator)

Source: GM¹X CalcVerse — https://calculators.geekmidst.com/calculators/weft-yarn-requirement-calculator