Quilt bordercalculator
Enter the size of your quilt center and the width of each border. You get the length of every border strip, how many width-of-fabric strips to cut, the fabric to buy and the finished size.
QuiltHelperEnter a quilt width and length, and a border width greater than zero.
Fabric to buy
1yard
Exact: 1.00 yards, rounded up to the next 1/8 yard
Cut 8 strips 41⁄2" wide across the fabric and join them into four border strips. Your quilt grows from 60" × 72" to 68" × 80".
Cutting list
Each border cut from its own fabricBorder layout
Border fabric for common quilt sizes
One 4" finished border with butted corners, cut from 42" usable fabric. Sizes are the quilt center before the border.
Swipe the table sideways to see every column.
| Quilt | Center | Side strips | Top & bottom | Strips | Fabric | Finished |
|---|---|---|---|---|---|---|
| Baby | 36" × 48" | 2 × 48" | 2 × 44" | 8 | 1 yd | 44" × 56" |
| Throw | 50" × 65" | 2 × 65" | 2 × 58" | 8 | 1 yd | 58" × 73" |
| Lap | 60" × 72" | 2 × 72" | 2 × 68" | 8 | 1 yd | 68" × 80" |
| Twin | 70" × 90" | 2 × 90" | 2 × 78" | 10 | 11⁄4 yd | 78" × 98" |
| Queen | 90" × 108" | 2 × 108" | 2 × 98" | 12 | 11⁄2 yd | 98" × 116" |
| King | 108" × 108" | 2 × 108" | 2 × 116" | 12 | 11⁄2 yd | 116" × 116" |
How to use this calculator
- Measure the quilt center. Measure through the middle, not the edges, in both directions.
- Choose how many borders and how wide. Enter the finished width of each border, from the inside out.
- Pick butted or mitered corners. Butted corners are quicker. Mitered corners need longer strips.
- Cut from the list. Each border shows its cut width, the length of every strip and how many width-of-fabric strips to piece together.
How the border math works
Each border is cut ½" wider than it finishes, for a ¼" seam on each side. With butted corners the side borders go on first and match the quilt length; the top and bottom borders then run across the new width. Every border after the first starts from the size the quilt has grown to.
Cut width = finished width + ½"Butted: sides = quilt length, top and bottom = quilt width + 2 × borderMitered: each strip = that side + 2 × border + 2"Strips per piece = (strip length − ½") ÷ (fabric width − ½"), rounded upFabric = total strips × cut width, rounded up to the next 1/8 yardExample: a 60" × 72" center with one 4" butted border, 42" fabric.
Side borders: 2 strips 72" long, each pieced from 2 width-of-fabric strips.
Top and bottom: 2 strips 68" long (60" + 2 × 4"), each pieced from 2 strips.
8 strips × 4½" = 36", so buy 1 yard. The quilt grows to 68" × 80".
Add a 2" inner border first and a 5" outer border instead, and the quilt grows to 74" × 86".
Butted or mitered corners?
Butted corners are the most common. You sew the side borders on, press, then sew the top and bottom borders across. They are quick and forgiving, and the strips are only as long as the quilt.
Mitered corners meet at a 45° seam, like a picture frame. They suit striped or directional border prints, and multiple borders can be sewn together first and mitered as one. Each strip has to run past the corner by the border width, so mitered borders use more fabric and take longer to sew.
Measuring for borders that lie flat
The edges of a pieced quilt top stretch as you handle and press it, so they are often longer than the middle. If you cut borders to match the edges, the quilt can end up with wavy, rippling borders.
Measure the length through the center and at two other places, then cut the side borders to the average or the center measurement. Pin the border to the quilt at the ends and the middle, easing in any fullness, before you sew. Repeat for the width once the side borders are on.
Common border mistakes
- Measuring along the edge. Edges stretch. Measure through the middle.
- Forgetting the first border. The second border is cut to the size after the first one is sewn on.
- Cutting at the finished width. Cut strips ½" wider than the width you want to see.
- Not enough length for miters. Mitered strips must run past the corner by the border width at each end.
- Joining strips off-center. When a border is pieced, many quilters center the seam or join with a diagonal seam so it is less visible.
Questions about quilt borders
How do I measure a quilt for borders?
Measure the quilt top through the middle in both directions, not along the edges. The edges stretch while you piece and press, so they are often a little longer than the middle. Cutting borders to the middle measurement keeps them from rippling.
How wide should quilt borders be?
There is no fixed rule. A common guide is to keep a border narrower than the blocks in the quilt, and to make an inner accent border about 1"–2" with a wider outer border. Try laying the fabric beside the quilt before you cut.
How much fabric do I need for a 4 inch border on a lap quilt?
For a 60" × 72" center with one 4" butted border, cut 8 strips 4½" wide from 42" fabric. That is 1 yard, and the quilt grows to 68" × 80".
Do mitered borders need more fabric?
Yes. Each mitered strip runs past the corner by the border width at both ends, plus a little extra to work with. In the 60" × 72" example the side strips are 82" long instead of 72".
Can I cut borders along the length of the fabric?
Yes. Cutting along the lengthwise grain avoids piecing and gives borders that stretch less, but it needs a piece of fabric as long as the longest border. This calculator assumes strips cut across the width of fabric and pieced where needed, which is how most quilters buy fabric.
Other calculators
How we check this calculator: cut lengths, strip counts and finished sizes are tested against hand-worked results for butted and mitered corners and for two and three borders, and thousands of random combinations are checked so every strip is long enough. Fabric amounts always round up. Last checked November 2026.