Fabric weight calculator: construction to estimated GSM

Estimates a woven fabric’s weight (g/m²) from warp and weft set plus the warp and weft yarn counts.

Formula

Convert yarn to Tex first (for Ne, Tex = 590.5 ÷ Ne). Warp g/m² = (warp ends/cm × warp Tex ÷ 10) × (1 + crimp). Weft g/m² = (weft picks/cm × weft Tex ÷ 10) × (1 + crimp). GSM = warp g/m² + weft g/m². Default crimp allowance is 6% (1 + 0.06).

Worked example

Warp: 40 ends/cm, Ne 30 → Tex = 590.5 ÷ 30 = 19.683. Weft: 30 picks/cm, Ne 20 → Tex = 590.5 ÷ 20 = 29.525. Crimp 6%. Warp g/m² = (40 × 19.683 ÷ 10) × 1.06 = 83.46. Weft g/m² = (30 × 29.525 ÷ 10) × 1.06 = 93.89. Estimated GSM = 83.46 + 93.89 = 177.35 g/m².

Estimated — indicative value.

Frequently asked questions

How is fabric weight calculated?

Compute (set × Tex ÷ 10) for warp and weft separately, multiply each by the crimp allowance, then add them. This gives an estimated GSM from construction; the exact weight is confirmed by weighing a sample per ISO 3801.

How does thread density affect weight?

With yarn count held constant, weight scales linearly with set: doubling warp or weft density doubles that direction’s weight contribution. A denser construction means a heavier fabric.

Why add a crimp allowance?

Yarn waves over and under as it interlaces, so it travels farther than the fabric dimension; that extra length adds weight. The 6% default is a typical estimate — higher for tight weaves, lower for open ones.

Why is the result an estimate?

The calculation cannot know actual crimp, finishing gain or loss, or moisture regain; these are approximated with a default crimp allowance. For sample approval, rely on the ISO 3801 weighed result.