Quilt Binding Calculator

Binding is calculated wrong more often than any other fabric in a quilt — usually by one strip, discovered at 11 pm with the shops shut. This calculator uses Missouri Star Quilt Co.'s published method: measure the perimeter, add a joining allowance, and divide by the usable fabric width.

Binding Calculator

Enter your finished quilt size and the width of binding strips you like to cut. Binding is the last fabric decision on a quilt — the first is the back, which the backing yardage calculator works out in panels and yards.

1 Enter your measurements

2 1/2 in is the standard cut for double-fold binding; 2 1/4 in gives a slightly tighter, flatter edge.
Missouri Star's method adds 20 in: enough for four mitered corners and the diagonal join that closes the binding loop.
Width of fabric actually usable per strip after the selvedges come off: 42 in for standard quilting cotton. Missouri Star's own tutorials divide by 40 in — if you prefer their margin, enter 40.

How it's calculated

Exactly as Missouri Star teaches it: binding length = perimeter + 20 in; strips = ⌈length ÷ usable width⌉; yardage = strips × strip width ÷ 36, rounded up to the nearest 1/8 yd. One honest difference: Missouri Star's tutorials divide by 40 in of usable width, building in extra caution. This calculator defaults to 42 in, the true usable width of standard quilting cotton with the selvedges removed — the field is adjustable, so fans of the 40 in margin can set it in one tap.

Choosing a binding strip width

Almost all modern quilts are bound with double-fold (French) binding: strips folded in half lengthwise, sewn to the front, and folded over to cover the edge. A 2 1/2 in cut is the standard — it finishes at about 3/8 in of binding showing on each side and handles batting up to medium loft without a fight.

Drop to 2 1/4 in for thin quilts, wall hangings, and a crisper, flatter edge; go to 2 3/4 in for high-loft batting or thick seams that need room inside the fold. Single-fold binding from 1 1/2–2 in strips suits miniatures and placemats but wears faster on a bed quilt's edges — the fold is the first thing to fray.

Straight-grain vs bias binding

The yardage on this page is identical either way — what changes is how you cut. Straight-grain strips are cut across the width of fabric, exactly as the strip count assumes, and are right for quilts with straight edges. Bias strips, cut at 45 degrees, are the choice for curved or scalloped edges because they bend around the shape without puckering.

Bias cutting consumes fabric differently in practice: you need a squarish piece to cut continuous bias, roughly the yardage figure this calculator gives, cut as one piece rather than as strips. If your yardage result is under about 1/2 yd and you are cutting bias, buy the 1/2 yd — the geometry of diagonal cuts wastes the corners.

How to use this calculator

  1. Add the four sides: perimeter = 2 × (width + length).
  2. Add the joining and corner allowance — 20 in in Missouri Star's method.
  3. Divide by the usable fabric width and round up: that is the number of strips to cut.
  4. Multiply strips by the strip width, divide by 36, and round up to the nearest 1/8 yd.

Worked example — a queen quilt

A queen quilt, 90 × 108 in, bound with the standard 2 1/2 in strips.

Step 1 — perimeter: 2 × (90 + 108) = 396 in.

Step 2 — add the joining allowance: 396 + 20 = 416 in of finished binding (Missouri Star's method adds 20 in for the corners and the final join).

Step 3 — strips: 416 ÷ 42 in of usable width = 9.9 → round up to 10 strips.

Step 4 — yardage: 10 strips × 2.5 in = 25 in; ÷ 36 = 0.69 yd → round up to 3/4 yd.

Related calculators

While you are cutting strips, our backing yardage calculator tells you how much fabric the back needs.

Frequently asked questions

Why add 20 inches to the perimeter?

The perimeter alone only measures the quilt's edges. The extra 20 in covers the four mitered corners (each one consumes more binding than the raw corner measurement suggests) and the overlap needed to join the two ends of the binding into a continuous loop with a diagonal seam. It is the allowance in Missouri Star's published method, and generations of quilters have found it lands right.

How much binding fabric does a baby quilt need?

For a 36 × 52 in crib quilt with 2 1/2 in strips: perimeter 176 in + 20 = 196 in; ÷ 42 = 5 strips; 5 × 2.5 ÷ 36 rounds up to 3/8 yd. Small quilts are why the joining allowance matters proportionally more — on a baby quilt it is over 10% of the total length.

My binding fabric is a fat quarter. Can I use it?

A fat quarter (18 × 22 in) yields about seven 2 1/2 in strips of 22 in each — roughly 154 in of binding. (Cut the strips across the 18 in side: seven 2 1/2 in strips fit, and each one runs the fat quarter's full 22 in length.) That covers small projects: placemats, wall hangings up to about 30 × 36 in. The calculator's strip math works the same; compare its length figure against 154 in.

Should binding be cut on the lengthwise grain instead?

Lengthwise-grain strips (cut parallel to the selvedge) stretch least and some quilters swear by them for competition quilts. The trade-off: a standard width of fabric only gives as many strips as fit along the bolt length you buy, so yardage planning changes. For everyday quilts, crosswise strips — what this calculator assumes — are the norm and behave perfectly well.

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