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Weaving Warp Calculator

Enter the width in the reed, the ends per inch and the finished length, and get the number of warp ends, the length to wind per end, the yarn for the warp and the weft, and how many cones to buy. Every assumption is yours and is shown.

Warp ends

244

104.074 in per end · 705.391 yd (645.009 m) of warp · 4.724 ends per cm

Weft: 667 picks · 407.611 yd (372.72 m)

Estimated finished width 18.05 in.

Warp
Weft and yarn (optional)

Estimates from the values you enter: density, shrinkage, take-up, waste and surplus are your choices. Keep a margin, especially with a new yarn.

How it works

  1. Enter the width in the reed (inches), the ends per inch and any extra selvedge ends.
  2. Enter the finished length, the shrinkage and take-up you expect, the fringe on each side, the loom waste and any sample.
  3. Optionally add picks per inch for the weft, and the yards on one cone to count cones.
  4. Read the ends, the length per end and the yardage, then copy the plan.

What people use it for

  • Before winding a warp

    Know how many ends to wind and how long, so the warp is neither short nor wasteful.

  • Buying yarn

    Turn the yardage into a number of cones, with the weft counted separately.

  • Comparing densities

    See what going from 12 to 15 ends per inch does to the ends and the yardage of the same scarf.

Questions

What are the formulas?
Ends = width × ends per inch, rounded up, plus the selvedge ends. Length per end = finished length ÷ (1 − shrinkage) ÷ (1 − take-up) + 2 × fringe + loom waste + sample. Warp yards = ends × length per end ÷ 36. Picks = the length on the loom (finished length ÷ (1 − shrinkage)) × picks per inch, rounded up, and weft yards = picks × width × (1 + surplus) ÷ 36.
Does it recommend a density or a shrinkage?
No. The ends per inch, shrinkage, take-up, waste and surplus are values you choose from your yarn, your loom and your own samples. The page only does the arithmetic.
What is take-up?
The length lost because the yarn goes over and under the weft. Shrinkage is the further change in length after washing. Both are entered as percentages of the length and applied one after the other: the length is divided by (1 − percentage). Some guides add the percentage instead, which gives slightly shorter results for the same figure.
Why is the estimate not exact?
Real weaving varies with tension, beat and yarn. Treat the plan as a careful estimate and keep a margin, especially for the first project with a new yarn.