π§Ά Quilt Binding Calculator
Binding length, strip count, and yardage for any quilt size.
Binding strips needed
How to Use the Quilt Binding Calculator
Enter your quilt's finished length and width, pick a strip width, and set the usable width of your fabric. The calculator adds the standard 10 inches for corners and joins, divides by the width of fabric for the strip count (always rounded up), and converts strips to yardage. Buy the rounded-up yardage; binding is the wrong place to economize.
Enter quilt length and width in inches, after quilting (quilts shrink slightly).
Choose strip width: 2.5 inches standard, 2.25 for minis, 2.75 for thick batting.
Hit Calculate Binding. Cut the strips, join diagonally, and press before attaching.
How Binding Math Works
The perimeter is the binding's path around the quilt. Ten extra inches cover mitered corners and the diagonal join where strip ends meet. Each strip runs the full usable width of fabric, so the strip count is the ceiling of length divided by WOF: fractional strips do not exist. Yardage is strips times cut width, converted from inches to yards.
Worked example, verified: 60 Γ 80 inch quilt, 2.5-inch strips, 42-inch WOF. Perimeter: 2 Γ (80 + 60) = 280 inches. Plus 10: 290 inches of binding. Strips: 290 Γ· 42 = 6.905, rounded up to 7 strips. Yardage: 7 Γ 2.5 = 17.5 inches of fabric = 0.486 yards, so buy a half yard. The 7 strips give 294 inches of binding, 4 inches of slack over the 290 needed, which is exactly the comfort margin you want.
Strip Width: Which to Choose
2.5 inches is the default because it wraps standard cotton batting with a comfortable grip and finishes around 3/8 inch wide on the front. Drop to 2.25 for wall hangings, table runners, and minis, where a chunky binding would overwhelm the scale. Go to 2.75 or 3 inches for high-loft or wool batting, which needs more wrap to enclose the thicker sandwich. The width also interacts with technique: machine-attached bindings want the standard width for the seam allowances to land right, while hand-finished bindings forgive a sixteenth either way. When in doubt, cut 2.5 and test-wrap a corner scrap before cutting all the strips.
Joining Strips and Mitering Corners
Join strips with 45-degree diagonal seams: lay two strip ends right sides together at a right angle, sew corner to corner, trim the seam to a quarter inch, press open. The diagonal spreads bulk across several inches instead of stacking it in one lump, and the binding feeds flat through the machine. At corners, stop a quarter inch from the edge, fold the binding up at 45 degrees, then back down along the next side to form the miter; the fold does the geometry for you. Join the final ends with the same diagonal seam, leaving a few inches of working room. Press the whole binding in half lengthwise, wrong sides together, before attaching, and the folded edge becomes your stitching guide on the back.
Tips for Binding Success
Cut strips across the width of fabric, not along the lengthwise grain, unless you need bias for curves; cross-grain has slight give that hugs the edge. Starch strips lightly before pressing in half for crisper handling. Walk the binding around the quilt before sewing to confirm the length; discovering a shortage mid-seam is preventable. For scrappy bindings, piece short strips diagonally into one long run first, then measure against the requirement. And always make a little extra: a 290-inch requirement with 294 inches of strips is perfect, while 289 inches is a tragedy. Round up, every time.
A Second Worked Example: The Table Runner
An 18 by 54 inch table runner with 2.25-inch strips and 42-inch usable fabric. Perimeter: 2 times (54 plus 18) is 144 inches. Plus 10: 154 inches of binding. Strips: 154 divided by 42 is 3.67, round up to 4 strips. Yardage: 4 times 2.25 divided by 36 is 0.25 yards, a fat quarter's worth. Small projects sip binding; the same math on a king quilt drinks yards.
Table runners are the ideal first binding project: four strips, straight edges, done in an evening. If the corners intimidate you, practice the miter on the runner before touching the quilt. Mistakes on a runner are lessons; mistakes on a finished quilt top are heartbreak.
Bias vs. Straight-Grain Binding
Straight-grain binding, cut parallel to the selvage, suits straight edges: stable, economical, easy. Bias binding, cut at 45 degrees, stretches and curves, which makes it mandatory for scalloped edges, curved quilts, and round table toppers. The trade is fabric: bias strips nest less efficiently, so a curved project needs noticeably more yardage than the straight formula suggests.
Bias also wears better on high-use edges because no single thread runs the full length of the fold; the diagonal threads share the stress. For a baby quilt or a well-loved throw, bias is worth the extra cutting. For a wall hanging that never gets touched, straight grain is plenty. Cut bias with a rotary cutter and a long ruler, handle the strips gently (they stretch), and starch lightly before sewing to tame the wobble.
Common Binding Mistakes
First: cutting exactly the perimeter with no extra. The 10 inches for corners and joins is not optional; binding cut to the exact perimeter always comes up short at the final join. Second: joining strips with straight seams. Straight seams stack four layers of bulk at one spot; diagonal seams distribute it and disappear into the fold.
Third: pressing both seam allowances the same way, which makes a lump. Press diagonal joins open. Fourth: attaching binding before trimming the quilt square. Quilt first, square the edges, then bind; binding a wavy edge locks the wave in permanently. Fifth: machine-stitching the front and hand-finishing the back without testing the stitch length on a scrap sandwich first. The batting thickness changes everything, and the test sandwich takes two minutes.
Worked Example: The King-Size Quilt
A king quilt finishing at 110 Γ 110 inches: perimeter = 440 inches. Add 12 inches for corners and joining: 452 inches of binding needed. Standard 2.5-inch strips cut across a 42-inch usable width give about 40 inches per strip after seam allowances: 452 / 40 = 11.3, so 12 strips. At 2.5 inches each, that is 30 inches of fabric, or 7/8 yard (buy 1 yard for safety).
For a queen at 90 Γ 108: perimeter 396 + 12 = 408 inches, 408 / 40 = 10.2 β 11 strips, 27.5 inches of fabric. The formula scales cleanly: (perimeter + 12) / 40, rounded up, times strip width. When in doubt, cut one extra strip; running short 20 inches from the end is the classic binding heartbreak.
The Geometry of Mitered Corners
Mitered corners work because of a simple fold sequence, not talent. Stop stitching 1/4 inch from the corner, fold the binding up at 45 degrees, then fold it back down along the next edge: the fold creates a perfect miter automatically. The 45-degree angle is doing all the work; your job is just stopping at the right mark.
The most common failure is stopping at the wrong distance: too early leaves a gap, too late bunches the corner. Mark the 1/4-inch point with a pin until the motion is muscle memory. Pressing the miter before hand-stitching the back locks it in place. A well-mitered corner lies flat and square; if yours does not, the fold angle was off, not your skill.
Pre-Cut Binding vs. DIY Strips: The Real Comparison
Pre-cut binding (usually 2.5-inch jelly-roll strips or packaged bias tape) saves 30 to 45 minutes of cutting and is perfectly consistent in width. It costs 2 to 3 times more per yard than cutting from yardage, and the color choices are whatever the manufacturer picked. For a scrappy or planned-color binding, pre-cuts are convenient; for a specific fabric match, they rarely work.
DIY strips from yardage win on cost and control: exact fabric, exact width, and enough length for any quilt. The rotary cutter and ruler investment pays for itself on the second quilt. The time cost is real but overstated: an experienced quilter cuts binding for a queen in 20 minutes. Cut your own unless the deadline is truly tight.
Pro Tips for Crisp Corners
Starch the binding strips before attaching. Light starching adds body that makes the fold crisp and the stitching easier to control; it washes out later. This one step separates amateur-looking binding from professional-looking binding more than any other.
Hand-stitch the back with a blind stitch and a single thread, not doubled: doubled thread tangles and shows. And bury your knots between the binding and the quilt rather than on the surface. Invisible finishing is the whole point of hand binding; the stitches should be felt, not seen.
Frequently Asked Questions
How much binding do I need for a quilt?
Measure the perimeter, add 10 inches for corners and joining, then divide by the usable width of fabric (about 42 inches) for the strip count. A 60 Γ 80 inch quilt: 280-inch perimeter + 10 = 290 inches Γ· 42 = 6.9, so 7 strips. The calculator above does this for any size.
How wide should quilt binding strips be cut?
2.5 inches is the standard for most quilts, giving a finished binding about 3/8 inch wide. Use 2.25 inches for a narrower finish on wall hangings and minis. Cut wider (2.75 to 3 inches) for thick batting like high-loft poly.
How much fabric for quilt binding?
Strips Γ strip width Γ· 36 = yardage. Seven 2.5-inch strips need 7 Γ 2.5 Γ· 36 = 0.49 yards, so buy a half yard. Fat quarters work for small quilts: one fat quarter yields about five 2.5-inch strips across its 22-inch side.
Why add 10 inches to the perimeter?
The extra covers the four mitered corners (each eats a few inches of maneuvering room) plus the overlap needed to join the strip ends diagonally. Skipping it is the classic reason binding comes up short 6 inches from the finish line.
What is WOF in quilting?
Width of fabric: the usable width selvage to selvage, about 42 to 43 inches for quilting cotton after trimming. Binding math divides by WOF because each strip is cut across the full width. Always use usable width, not the 44/45-inch bolt width.
Should binding be cut on the bias or straight grain?
Straight grain (across the width) is standard and easiest; it is also the most economical. Bias binding is needed only for curved edges and scallops, because bias stretches around curves. For straight-edged quilts, straight grain is stronger and simpler.
How do you join binding strips?
With diagonal seams at 45 degrees, which distribute bulk so the binding stays flat. Overlap strip ends at right angles, sew corner to corner, trim to a quarter-inch seam, and press open. Straight seams create a lump that shows on the finished edge.
How much binding for a king-size quilt?
A 108 Γ 108 inch quilt has a 432-inch perimeter; plus 10 is 442 inches Γ· 42 = 10.5, so 11 strips. At 2.5 inches each, that is 27.5 inches of fabric width, or about 3/4 yard. Big quilts eat binding fast, which is why the calculator matters.
Can I use a fat quarter for binding?
For small quilts, yes. A fat quarter (18 Γ 22 inches) cut into 2.5-inch strips along the 22-inch side yields five 22-inch strips, about 110 inches total. That binds a quilt with up to a 100-inch perimeter, like a baby quilt or wall hanging.