Quilt Border Calculator

Enter your quilt center and up to three border widths. You get each border’s strip lengths, the strips to cut from your fabric, the yardage per border, and the quilt size growing border by border.

Your Quilt Center and Borders

Corners

Butted: sides go on first, then top and bottom overlap them, the everyday corner.

Fine-tune: fabric width

All Borders

1 ⅜yards

2 borders · finished quilt 66 × 78 in

Butted: sew the two side strips on first, press, then the top and bottom across them.Measure the quilt through its middle before cutting each border.
  • Border 1: 2″ (7 strips at 2.5″)½ yd
  • · sides 2 × 66″, top/bottom 2 × 58″→ 58 × 70 in
  • Border 2: 4″ (7 strips at 4.5″)⅞ yd
  • · sides 2 × 70″, top/bottom 2 × 66″→ 66 × 78 in
  • Total border fabric1 ⅜ yd

The Formulas

Butted Borders

side strips = center length  ·  top and bottom = center width + 2 × border width

Mitered Borders

each strip = its side + 2 × border width + 2 in working room

Strips and Yardage

strips = ⌈total strip length ÷ usable width⌉  ·  yards = strips × (border width + ½) ÷ 36

Strips cut selvage to selvage and joined where a side runs longer than the fabric. Each border is priced on the quilt as it stands when that border goes on: border 2 wraps a quilt already grown by border 1.

Worked Example

A 54 × 66 in center with a 2 in inner border and a 4 in outer border, butted, 40 in usable fabric:

  • Border 1 (2 in): sides 66 in ×2, top and bottom 58 in ×2 → 248 in → 7 strips at 2½ in cut → ½ yd. The quilt is now 58 × 70.
  • Border 2 (4 in): sides 70 ×2, top and bottom 66 ×2 → 272 in → 7 strips at 4½ in cut → ⅞ yd. Finished: 66 × 78.
  • Mitering the same borders adds the border width back at each corner end: a yard total grows by roughly an eighth.

How to Measure Your Inputs

  • Measure the center through the middle, not the edges, after piecing: edges stretch and the middle tells the truth. Cut side borders to that middle measurement and ease the edge to fit; wavy borders start with edge measurements.
  • Border widths are finished. The calculator adds ½ in of seam allowance to every cut.
  • Directional or striped border fabric? Cut lengthwise along the bolt instead; you need strips as long as each side, no joins: usually the quilt length in yardage.

Assumptions and Defaults

  • Strips cut cross-grain and pieced with diagonal seams where a side outruns the fabric width; the strip count carries the join allowance.
  • Butted order: sides first, then top and bottom. Swap the order and the two lengths trade places: totals stay the same.
  • Mitered strips carry 2 in of working room per strip beyond the geometric need.
  • Yardage per border rounds up to the next ⅛ yard, so each border is a buyable cut on its own.

Border Questions, Answered

How wide should quilt borders be?
Quilt borders are usually 1 to 2½ in wide for an inner border and 4 to 6 in for an outer one, since a border wider than one block tends to overpower the center. Borders in graduated widths, narrow, wider, then widest, tend to look best, although your own quilt is always the better guide.
How much fabric do I need for a quilt border?
A quilt border needs the four strip lengths added together and divided by the usable fabric width, rounded up for the strip count, then multiplied by the cut width (finished plus ½ in) and divided by 36. The example above prices a 2 in and a 4 in border at ½ and ⅞ yd.
Should I cut quilt borders lengthwise or crosswise?
Crosswise borders, cut selvage to selvage, use the least fabric but need a join on the long sides, whereas lengthwise borders have no joins and no stretch. Lengthwise borders are worth it for stripes and show quilts, although you have to buy the full quilt length in yardage.
Should quilt borders have butted or mitered corners?
Butted corners are quicker and sturdier and are the default on bed quilts, whereas mitered corners suit a border fabric with a stripe or a print that should turn the corner like a picture frame. If you miter, cut the extra length the miter needs, which this calculator adds for you.
Why measure through the quilt’s middle for borders?
You measure through the quilt’s middle for borders because pieced edges stretch while you handle them, whereas the middle stays true. Cut the side borders to the middle measurement and ease the slightly longer edge to fit, since borders cut to a stretched edge ripple, the most common cause of a wavy quilt.