WOF strip / jelly-roll strip calculator
Patterns count in strips, and shops sell in yards. Type the usable width of fabric, the strip width and either a strip count or the total length of strip you'll sew end to end, and you get strips per cut, yards to buy and the length left over. It runs in your browser.
Twenty 2.5 inch strips from 40 inch usable width of fabric is 50 inches into the bolt, 1.39 yards, which rounds up to 1.5 yards.
- Runs in your browser
Your strips
Usable width after trimming selvages. Quilting cotton is usually about 40 in.
How deep each strip cuts into the bolt. Jelly-roll style is 2.5 in.
Total linear inches of strip after joins.
Extra inches for end-to-end joins. Leave 0 if you already padded the count.
one WOF cut — to cut — fabric — leftover —
Buy yards
A worked example
Twenty 2.5 inch strips from 40 inch usable WOF: 20 × 2.5 = 50 inches into the bolt = 1.39 yards, which rounds up to 1.5 yards the way shops cut. One WOF cut still gives you one 40 inch strip; leftover only appears when you start from a project length instead of a strip count.
How the math works
- One WOF cut = one strip whose length equals your WOF.
- Fabric depth = strips × strip cut width. Convert to yards (÷ 36) and round up to the nearest quarter yard.
- From project length: strips = length ÷ WOF, rounded up; leftover = (strips × WOF) − length.
For the whole quilt top, use the yardage calculator. For binding from perimeter, use the binding calculator.
Questions
What is WOF?
Width of fabric: the usable width, selvage to selvage, off the bolt. Quilting cotton is usually about 40 inches after you trim selvages (it is sold at 42 to 44). This calculator defaults to 40; type your real usable width.
Does this work for jelly rolls?
Yes, if you already have precut 2.5 inch strips and you want to know how many more to cut from yardage, or how much fabric a strip count will take. A commercial jelly roll is typically forty 2.5 inch strips; this tool prices the fabric depth into the bolt, not the precut pack.
What is leftover strip length?
When you work from a project length (total inches of strip you need), strips are whole WOF cuts. Leftover is the unused inches on the last strip after you join what you need. Keep it for scrappy binding or small projects.
Where does seam waste go?
Optional inches added to the length you need (or converted into extra strips in strip-count mode). Use it for join losses when you piece strips end to end, not for the quarter-inch seam inside a block.
Is this the same as the binding calculator?
Related, not the same. Binding works from quilt perimeter to strip count. This tool starts from how many strips (or how many inches of strip) you already know you need, so it suits jelly-roll math, sashing runs or any other WOF strip project.
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