Sett Calculator

Sett for Success

No need to do the math yourself — this simple tool recommends common weaving setts based on your yarn’s WPI. Just enter a number and get results you can actually use.

Weaving Sett Calculator

Enter the wraps per inch (WPI) of your yarn to see sett range suggestions using common reed sizes.



WPI ≠ Sett: Wraps per inch (WPI) is a great starting point, but sett also depends on structure, fiber, and personal preference.

  • Plain Weave Needs Space: For balanced plain weave, sett is typically half the WPI to allow room for the weft to pass through cleanly.

  • Twill Weaves Pack In More: Twills can handle higher setts—around two-thirds of the WPI—because the weave floats over more threads.

  • Lace Weaves Like to Breathe: For lace, leno, or open structures, sett is usually a bit looser—around WPI divided by 2.5.

  • The Calculator Rounds Smartly: Instead of exact math, this tool rounds to the nearest common sett size, making it practical for real-world reeds.

  • Weave a Sample!
    Even with a perfect sett estimate, nothing beats weaving a sample and wet-finishing it to test drape and density.

  • Check Your Reed Inventory: Sett is only part of the puzzle—you’ll need a reed and sleying pattern that can achieve it.

  • Trust Your Hands and Eyes: Use this as a starting point, not a rule. If the cloth looks too tight or too loose, adjust accordingly.