Enter your quilt size and strip width. You get the binding length, the strips to cut and the yardage for straight-grain binding, or, for curved edges, the single square of fabric that makes the whole binding as one continuous bias strip.
Your Quilt and Binding
Strip width cut width, before folding
Grain
Straight grain suits straight edges: nearly every quilt.
Fine-tune: allowance and fabric width
You Need
¾yards
10 strips × 2.5″, cut selvage to selvage
Cut 10 strips at 2.5 in, join them end to end on the diagonal, press in half, and bind.392 in of binding covers the 380 in perimeter with 12 in for corners and the join.
- Binding length392 in
- Strips to cut10 × 2.5″
- Fabric depth25 in
- Yardage¾ yd
The Formulas
Binding Length
binding length = 2 × (width + length) + 10–12 in for corners and the joinStraight-Grain Strips
strips = ⌈binding length ÷ usable fabric width⌉ · yards = strips × strip width ÷ 36Continuous Bias Square
square side = √(binding length × strip width), rounded upOne square, cut once on the diagonal and sewn into a tube, yields the whole binding as a single bias strip: no separate strips to join. The calculator checks the square against the seam allowances it loses and bumps it an inch when the fit is tight.
Worked Example
A queen quilt, 90 × 100 in, bound in 2½ in strips from 40 in usable cotton:
- Binding length: 2 × (90 + 100) + 12 = 392 in.
- Straight grain: 392 ÷ 40 → 10 strips, 10 × 2½ = 25 in of fabric → ¾ yd.
- Continuous bias instead: √(392 × 2.5) = √980 ≈ 31.3 → a 32 in square, just under a yard of fabric.
- Bias costs about a quarter yard more here: worth it only when the edge curves or the binding fabric is a stripe you want on the diagonal.
Binding Chart by Quilt Size
Computed by the calculator above: 2½ in strips, 40 in usable fabric, 12 in allowance.
| Quilt | Binding length | Strips | Yardage | Bias square |
|---|---|---|---|---|
| Crib 36×52 | 188 in | 5 | ⅜ yd | 23″ square |
| Throw 50×65 | 242 in | 7 | ½ yd | 26″ square |
| Twin 70×90 | 332 in | 9 | ⅝ yd | 30″ square |
| Full 84×90 | 360 in | 9 | ⅝ yd | 31″ square |
| Queen 90×100 | 392 in | 10 | ¾ yd | 32″ square |
| King 108×108 | 444 in | 12 | ⅞ yd | 34″ square |
How to Measure Your Inputs
- Quilt size: measure the quilted, trimmed quilt: binding goes on last, and quilting can pull an inch from the top’s cut size.
- Strip width: 2½ in is the double-fold standard; 2¼ makes a tighter, flatter roll many longarmers prefer; 2¾ fills out over a high-loft batting.
- Usable width: selvage to selvage minus the selvages: 40 in is the safe figure for 42/44 in quilting cotton.
Assumptions and Defaults
- Double-fold (French) binding: strips folded in half before sewing. Single-fold uses the same lengths at half the strip width.
- Strips join on the diagonal, which is where the 12 in allowance goes along with the four corners.
- The bias square is rounded up to the next whole inch, then checked: a square loses about half an inch each way to seam allowances when sewn into the tube, and the calculator sizes for that.
- Yardage rounds up to the next ⅛ yard. A jelly roll strip is 2½ in × about 42 in, the strip count doubles as a jelly-roll count.
Binding Questions, Answered
How much binding do I need for my quilt?
A quilt needs binding equal to its perimeter plus 10 to 12 inches, which is twice the width plus twice the length, with the extra covering four mitered corners and the final join. A 90 × 100 in queen therefore needs about 392 inches, just under 11 yards of finished binding, cut from ¾ yard of fabric.
How wide should I cut binding strips?
Binding strips are most often cut 2½ inches wide for double-fold binding, which finishes about ⅜ inch on the front. Cut 2¼ inches for a flatter, tighter finish or 2¾ inches over thick batting, and whichever width you choose, cut every strip the same so the binding rolls evenly around the quilt.
When do I need bias binding for a quilt?
A quilt needs bias binding when it has curved edges, scalloped borders, or rounded corners, whereas straight edges don’t need it. Bias also wears longer, because no single thread runs along the fold, and it sets stripes and plaids on the diagonal; for a straight-edged quilt, straight-grain binding is cheaper and simpler.
What size square for continuous bias binding?
The square for continuous bias binding is the square root of the binding length times the strip width, so 392 inches of 2½ inch binding needs √980, about a 32 inch square. The bias setting above does this arithmetic and the seam-allowance check for you.
How many binding strips do I cut?
The number of binding strips is the binding length divided by the usable fabric width, rounded up, so a queen needs 392 ÷ 40 = 10 strips. Each diagonal join uses a couple of inches, which the 12 inch allowance already covers.
Can I bind a quilt with a jelly roll?
Yes, you can bind a quilt with a jelly roll, since jelly roll strips are already 2½ × 42 in. The strip count above is the number of jelly roll strips to join, about six for a throw and ten for a queen; press them in half and bind as usual.
Should I use single-fold or double-fold binding?
Double-fold binding is the standard for quilts, because two layers of fabric wrap the edge and hold up to washing and wear. Single-fold binding, by contrast, suits small pieces that hang on walls, using half the fabric and offering about half the durability.
Continuous bias square method: Geta’s Quilting Studio.