Warp / beam yarn calculator

From warp density, width and beam length, find total ends and the warp yarn weight you need.

Formula

Total ends = warp density (ends/cm) × usable width (cm). Warp yarn (kg) = total ends × beam length (m) × Tex ÷ 1,000,000 × (1 + take-up + waste). Tex = dtex ÷ 10; for denier, Tex = denier ÷ 9. Enter take-up and waste as decimals (e.g. 3% → 0.03).

Worked example

24 ends/cm, 180 cm usable width → total ends = 24 × 180 = 4,320 ends. 167 dtex (= 16.7 Tex) yarn, 1,000 m beam, take-up 0.03 + waste 0.02 → warp yarn = 4,320 × 1,000 × 16.7 ÷ 1,000,000 × (1 + 0.03 + 0.02) = 72.144 × 1.05 = 75.8 kg.

Frequently asked questions

How is warp yarn quantity calculated?

First, total ends = density (ends/cm) × usable width (cm). Then warp yarn (kg) = total ends × beam length (m) × Tex ÷ 1,000,000, multiplied by (1 + take-up + waste). Get Tex from dtex ÷ 10.

Why add take-up and waste?

Take-up is the warp shortening as it interlaces during weaving; waste is yarn lost in warp preparation and weaving (knotting, breaks, beam head and tail). Both are added as allowances on top of the net yarn, otherwise the beam runs short.

I use denier yarn — how do I convert to Tex?

Tex = denier ÷ 9. E.g. 150 denier = 16.67 Tex. For dtex, Tex = dtex ÷ 10; 167 dtex = 16.7 Tex. The formula always takes Tex because the ÷ 1,000,000 constant is Tex-based (g per 1000 m).

Should I enter usable width or reed width?

Enter the actual warp width wound on the beam — the usable width in the reed — not the finished fabric width. Warp is wider because of shrinkage and selvedge allowances.