Thimblewise

Quilt Border Calculator

Enter your quilt center size and border widths to find strip counts, cut lengths and yardage for each border layer.

Leave at 0 for a single border.
Leave at 0 if not needed.
Usable width after trimming selvages.

How border yardage math works

  1. Cut width. Each strip is the finished border width plus a half inch for seam allowances (quarter inch on each long side).
  2. Strip length. For butted corners, side strips equal the quilt length and top/bottom strips equal the quilt width plus twice the border width. For mitered corners, every strip is the quilt dimension plus twice the border width plus 4 inches to sew and trim the miter.
  3. Strips to cut. If every edge fits within the usable width of fabric (WOF), cut four strips, one per edge. Otherwise sew WOF strips end to end into one long strip and cut the four edges from it. Each join uses ½", so n strips give n × fabric width − (n − 1) × ½".
  4. Yardage. Total WOF strips times the cut width gives the total inches of fabric needed along the length grain. Divide by 36 and round up to the next eighth of a yard.

Example: 50" × 60" quilt center, single 4" butted border, 40" fabric. Cut width: 4½". Sides: 2 × 60"; top and bottom: 2 × 58"; 236" in all. Six joined strips give 6 × 40 − 5 × ½ = 237½", enough. 6 × 4½" = 27" = ¾ yard. Finished quilt: 58" × 68".

Border yardage chart

Butted corners, 40" usable fabric width.

QuiltCenterBordersFinished sizeFabric
Baby36" × 52"3"42" × 58"½ yd
Throw50" × 60"4"58" × 68"¾ yd
Twin60" × 80"4"68" × 88"1 yd
Queen80" × 90"4" + 6"100" × 110"3⅛ yd
King96" × 96"4" + 6"116" × 116"3⅝ yd

Border tips

Questions quilters ask

What is the difference between butted and mitered corners?

Butted (or squared) corners are the simpler method: the side border strips run the full length of the quilt, and the top and bottom strips run between them. Mitered corners meet at a 45-degree angle like a picture frame. Mitered corners look more polished but require longer strips and more careful sewing.

How much extra fabric do mitered corners need?

Each mitered strip runs the full length of its edge plus the border width at both ends, so cut it the quilt dimension plus twice the border width, plus a few inches to sew and trim the miter. This calculator adds 4 inches. For a 4-inch border on a 60-inch side, that is a 72-inch strip instead of 60 inches.

Should I cut border strips lengthwise or crosswise?

Crosswise (across the width of fabric) is most economical and is what this calculator assumes. Lengthwise strips have less stretch because they run along the grain, which can be helpful for long borders. If you cut lengthwise, you will likely need more fabric because strips are limited to the yardage you buy.

How do I keep borders from getting wavy?

Measure through the center of the quilt, not along the edges, to determine the border length. Pin the border to match this measurement. Edges often stretch during piecing, and using the center measurement keeps the quilt square. Press seams toward the border.

Do I need to add seam allowance to the border width I enter?

No. Enter the finished (visible) border width. The calculator adds the standard quarter-inch seam allowance on each long side, so a 4-inch finished border becomes a 4.5-inch cut strip.