Quilt border calculator
Enter your quilt center and up to three border widths to get strips, yardage and the finished size after each border.
Enter your numbers
How it is calculated
Each border needs two side strips as long as the quilt's current length, and a top and bottom strip as long as the current width plus the two new side borders. So the running length per border is 2 x length + 2 x (width + 2 x border width), plus 10 inches for joining strips. Strips are cut across the fabric width at the finished border width plus 1/2 in for seam allowances, and the running length divided by usable width gives the strip count.
After each border the quilt grows by twice the finished border width in both directions, and the next border is calculated from that new size.
Worked example
A 48 x 60 in center with a 2 in border then a 4 in border: border 1 needs 234 running inches, 6 strips cut at 2 1/2 in, buy 1/2 yard, and the quilt becomes 52 x 64. Border 2 needs 258 running inches, 7 strips cut at 4 1/2 in, buy 7/8 yard, and the quilt finishes at 60 x 72 in.
Common questions
- Do I cut border strips crosswise or lengthwise?
- This tool assumes crosswise strips (cut selvage to selvage) joined to length, which is the most fabric-efficient and by far the most common. Lengthwise borders avoid joins but need yardage as long as your quilt; for that, buy the length of your longest border plus a few inches.
- How wide should quilt borders be?
- A common guideline is to keep each border between about 1/2 and 1/4 of the block size, with wider outer borders than inner ones. There is no rule; audition widths by folding fabric next to the quilt.
- Why measure through the middle of the quilt before cutting borders?
- Edges stretch during piecing, so the edge measurement is often bigger than the true size. Cutting borders to the middle measurement and easing the edge to fit keeps the quilt square and flat.
- Does the calculator include seam allowance?
- Yes. You enter the finished border width and it cuts strips 1/2 in wider to cover both 1/4 in seams.
Related tools
SewCalc results are careful estimates based on standard practice. Fabrics, brands and personal technique vary, so always confirm measurements against your own pattern or project before cutting.