I was at a yarn marketplace with a couple of friends. A friend, also named Susan, was interested in a skein of yarn and asked me if there was a sufficient amount to weave a scarf. I walked her through a short math lesson, but the moment got me thinking that other weavers may wonder about the same thing.
Whether you are a newish weaver like my friend Susan or someone who’s just rediscovered a precious skein in their stash, this calculation can help guide you on your project estimations.
Here are the rough guidelines I use in my calculations:
- A 3-yard warp is sufficient for a 72″ scarf, allowing 1 yard for take-up and loom waste, including fringe, on a shaft loom. On a rigid-heddle loom, a 2.5-yard warp is sufficient.
- Scarves are generally between 4 and 10 inches in width.
- Sett is harder to determine, although you can wrap a few strands around your finger or a ruler to roughly estimate how many strands are in ½ inch.
- Weft yardage is about two-thirds of warp yardage.
I usually do the following math in my head, but you could use your phone’s calculator to do a better job.
Here's a close-up of the skein before opening it up (left). Estimating sett by wrapping the yarn around a finger (or using a ruler) for about a half inch (right).
Calculation Examples
If you want to use the skein only for warp, divide the number of yards in the skein by 3 for a shaft loom or 2.5 for a rigid-heddle loom. The resulting number divided by your sett will determine your scarf‘s width.
For example, a skein of 250 yards divided by 3 yields about 80 warp threads. Sett at 10 epi, that would result in an 8-inch-wide warp on a shaft loom. The same skein of yarn would yield about 100 warp threads or a 10-inch-wide warp (250 divided by 2.5) on a rigid-heddle loom.
Multi-Shaft Example #1: Warp Only Estimate
Skein Length: 250 yards
Desired Warp Length: 3 yards
Warp Threads Possible: 250 ÷ 3 = 80 warp threads
Sett: 10 epi
Maximum Scarf Width: 80 warp threads ÷ 10 epi = 8"Rigid-Heddle Example #1: Warp Only Estimate
Skein Length: 250 yards
Desired Warp Length: 2.5 yards
Warp Threads Possible: 250 ÷ 2.5 = 100 warp threads
Sett: 10 epi
Maximum Scarf Width: 100 warp threads ÷ 10 epi = 10"
If you want to know how many yards you need for warp and weft, approach the calculation a little differently. Multiply your estimated sett by the desired width, then multiply by 3 yards (or 2.5 yards) to see how many yards you need for the warp. For the weft, estimate two-thirds of the warp yardage. Add the two numbers together for the total number of yards needed for a scarf.
For example, if your estimated sett is 10, and you want a 10" scarf, multiply 10 by 10 to get 100 warp threads. Multiplying 100 warp threads by your 3-yard warp length equals 300 yards needed for the warp. Two-thirds of 300 is 200, needed for the weft. Therefore, you need 500 yards (or 2 skeins of 250 yards each) to weave a 10 x 72″ scarf on a shaft loom.
Multi-Shaft Example #2: Warp and Weft Estimate
Sett: 10 epi
Desired Scarf Width: 10"
Warp Threads Needed = 10 epi x 10" = 100 warp threads
Desired Warp Length = 3 yards
Warp Length Estimate = 100 warp threads x 3 yards = 300 yards neededWeft Length Estimate = 300 x ⅔ = 200 yards needed
Total Yards Needed = 300 (warp) + 200 (weft) = 500 yards
For a rigid-heddle loom, multiplying 100 warp threads times your 2.5-yard warp length equals 250 yards. Two-thirds of 250 yards is roughly 160 yards. That means you need 410 yards to weave the same scarf. You’ll still need to purchase 2 skeins, but you’ll have more left over for your next project.
Rigid-Heddle Example #2: Warp and Weft Estimate
Sett: 10 epi
Desired Scarf Width: 10"
Warp Threads Needed = 10 epi x 10" = 100 warp threads
Desired Warp Length = 2.5 yards
Warp Length Estimate = 100 warp threads x 2.5 yards = 250 yards neededWeft Length Estimate = 250 x ⅔ = 160 yards needed
Total Yards Needed = 250 (warp) + 160 (weft) = 410 yards
These calculations are estimates at best, but if you are flexible in length and width, they will help you buy your next souvenir skein or skeins with more confidence.
Weave well,
Susan
Susan E. Horton’s grandmother taught her to knit, and her mother taught her to sew. Weaving came much later but has become her favorite among the fiber arts.
Originally published July 19, 2019; updated March 29, 2024.