Weaving Warp Length Calculator
Warp is the set of threads that run the length of a loom. This works out how long to cut each warp thread, and how many ends you need, for a piece of a given finished size.
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How it works
Start with the finished length. Add take-up, the extra warp that the weaving pulls into the cloth, as a percentage of that length. Then add the loom waste, the length tied off at each end that cannot be woven.
The number of ends is the width in inches times the sett, which is how many threads you want in each inch. The total yarn is the warp length times the ends. The ends are rounded up so no thread is missing.
Worked example
For a piece 2 yd long and 12 in wide, with 10% take-up and 1 yd of loom waste, cut each warp thread to 3.2 yd. That is 288 ends, and about 922 yd of yarn in all.
Questions
What is take-up?
Take-up is the extra warp that the weaving pulls into the cloth. Each thread bends over and under the others, so it ends up shorter than it started. Tighter weaves usually take up more.
What is a sett?
The sett is how many warp threads you want in each inch of width. Check your pattern or your reed, since the right number depends on the yarn and the cloth you want.
Why add loom waste?
The last few inches at each end of the warp cannot be woven, because they are held by the ties and beams. Adding a little length keeps you from running short.
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