A Free Calculator · Straight-Grain Double-Fold · Updated 2026
How much binding fabric does your quilt actually need?
Binding fabric is not a guess — it's perimeter math plus a small buffer for corners and
joins. Enter your quilt dimensions, strip width, and fabric width below, and the
calculator tells you exactly how many strips to cut and how many yards to buy.
Every formula is shown, nothing is a black box.
Strips to cut·Total binding length·Yards to buy
Read this first
This calculator covers straight-grain, double-fold binding — the standard for most bed and
lap quilts. It does not cover bias binding (used for curved edges) or single-fold binding.
The WOF default of 42 inches is a conservative post-wash figure; adjust it to match your
actual fabric. The corner/join buffer is editable — 10 inches is a minimum, and more is
always safer. The arithmetic is exact; the accuracy depends on your inputs.
Enter your quilt dimensions and fabric specs. The results update as you type. All four output numbers come directly from the formulas shown below the tool.
Your quilt dimensions
in
Measure the finished quilt top — the longest side.
in
The shorter dimension, measured across the finished top.
Your fabric and strip specs
in
2.5" is standard for double-fold binding. See the strip-width table below for finished-edge widths.
in
Width of fabric after removing selvedges. 42" is a common post-wash conservative figure for 44"-wide quilting cotton.
in
Mitered corners and diagonal seam joins consume extra length — 10" is the minimum. Many quilters use 12–15" for peace of mind.
Buy of binding fabric
Perimeter
Total binding length (with buffer)
Strips to cut (at WOF)
Binding fabric
The formulas, in full
Nothing here is a black box. These are the exact calculations the tool runs — the same
arithmetic you could do with a pencil. The only judgment calls are the inputs you supply.
How each number is derived
1 — Perimeter (total distance around all four edges)
perimeter (in) = 2 × (quilt_length + quilt_width)
2 — Total binding length (perimeter plus buffer for corners and joins)
3 — Number of strips to cut (always rounded up — you cannot cut a partial strip)
strips = Math.ceil(binding_length ÷ usable_WOF)
4 — Binding fabric needed in inches (strips across the fabric grain)
binding_fabric_inches = strips × strip_width
5 — Binding fabric in yards (there are 36 inches per yard)
binding_yards = binding_fabric_inches ÷ 36
Common binding strip widths — finished edges at a glance
Strip width determines both how much fabric you cut and how wide the finished binding
appears on the quilt's edge. Wider strips wrap more generously around thick batting;
narrower strips give a crisper, tighter border. All figures below are for standard
double-fold binding and are approximate — actual finished width varies with your
seam allowance, batting thickness, and how firmly you pull the binding to the back.
Strip width (cut)
Folded working width
Approx. finished edge width
Best for
2.25 in
~1.125 in
~¼–⅜ in
Thin batting (cotton batting, wall hangings); gives a narrow, tailored look. Less forgiving of uneven backing.
2.5 in
~1.25 in
~⅜–½ in
Standard for most quilts — bed quilts, lap quilts, medium batting. The most common starting point.
2.75 in
~1.375 in
~½–⅝ in
Thick or fluffy batting (wool, high-loft poly); generous overlap for easier hand-stitching on the back.
Finished widths are approximate. They vary with batting loft, how tightly the binding is
pulled to the back, and your seam allowance when attaching the binding. Cut a short test
strip and wrap it around a layered scrap to confirm before cutting the full binding.
Why each part of the formula exists
The four steps are not arbitrary — each one reflects something real that happens during
the binding process. Understanding the why makes it easier to adjust the inputs for your
specific quilt.
Perimeter is the floor, not the ceiling
The raw perimeter tells you the minimum length of binding that could theoretically wrap around the quilt with zero waste. In practice you always need more, because corners require folding extra fabric into a miter rather than lying flat, and joining strips end-to-end at a diagonal seam consumes a few extra inches at each join. Treating the perimeter alone as your shopping number is the most common cause of running short on binding.
The buffer is a judgment call — 10" is the minimum
Ten inches covers the corner miters on a typical quilt with a bit to spare. If your quilt has many joins in the binding (because your strips are short or you bought from a fat-quarter bundle), increase the buffer. If you are finishing a very large quilt — a king-size top can have a perimeter of 500+ inches — a 12–15 inch buffer is more comfortable. The calculator makes this editable rather than locking in a number, because it depends on your technique and how much buffer you want on the final join.
Ceiling division guarantees you have enough strips
Dividing binding length by WOF tells you how many fabric-width passes you need. Because you cannot cut a fraction of a strip from a piece of fabric, the calculator always rounds up. A result of 6.1 strips means you cut 7 — leaving a small scrap rather than running short. The cost of one extra strip is a few inches of fabric. The cost of one strip short is unpicking binding from the final stretch of the quilt.
Strip width × strip count = the fabric you cut from the bolt
Binding fabric is cut in strips across the grain — each strip is one strip-width tall and one WOF wide. If you need 7 strips of 2.5-inch binding, you are cutting a piece of fabric 17.5 inches tall (7 × 2.5") and your WOF wide. That 17.5 inches divided by 36 gives you the yardage: a little under half a yard. The calculator always shows both the inches and the yards so you can verify the arithmetic before you buy.
How to get the most accurate estimate
Four inputs drive the result. The two that vary most between quilters are WOF and the
corner buffer — getting those right does the most to make the number reliable.
Measure your quilt top, not the pattern size
Pattern dimensions and finished dimensions rarely match exactly — fabric stretches, seam allowances vary slightly, and borders add or subtract differently than planned. Measure your actual quilt top before you calculate binding. The difference between a 58-inch and 60-inch width adds 4 inches to the perimeter — small, but worth catching before you cut.
Prewash your binding fabric and measure WOF after
Quilting cotton typically prints on 44-inch bolts, but washing causes shrinkage and the selvedges need to come off. The real usable WOF for most pre-washed quilting cotton lands between 40 and 42 inches. If you skip prewashing, using 42 inches is a safe assumption. If you prewash, measure the fabric before you cut strips and enter your actual width — it directly affects how many strips you need.
Cut a test strip before committing your fabric
Fold a short scrap strip to double-fold width, wrap it around a layered test sandwich (top + batting + backing), and pin it through. This confirms that your chosen strip width produces the finished edge width you want and that it covers the backing cleanly. A few minutes with scraps prevents hours of unpicking a finished quilt.
Buy the next eighth-yard increment above the calculator's result
Fabric stores sell by the eighth yard (4.5 inches). If the calculator returns 0.49 yards, buy 0.5 yards (or 5/8 to be safe). A second trip to the store for a few more inches of the same fabric — especially from a cut piece — is often impossible once you are mid-project. A small overrun costs pennies and preserves your options.
Where to buy
Got your numbers? Here's where to pick up what you need:
The terms that appear in binding tutorials, pattern instructions, and fabric shop
descriptions — in plain English.
Binding
The strip of fabric sewn around the perimeter of a finished quilt to enclose the raw edges of the quilt top, batting, and backing. It is both structural (holding the layers together at the edge) and decorative (the visible frame of the quilt).
Double-fold binding (French-fold binding)
Binding cut from a strip that is pressed in half lengthwise before attachment, so the finished binding has two layers. The extra thickness hides the raw batting edge durably. The most common binding type for quilts. See also: single-fold.
Single-fold binding
Binding cut from a narrower strip and folded once rather than twice. Less common in quilting today; uses less fabric but is thinner and more likely to wear through at the corners over time.
Width of fabric (WOF)
The usable width of a piece of quilting cotton after the selvedges are removed. Typically 40–42 inches after washing for 44-inch bolts. The calculator divides total binding length by WOF to determine how many strips to cut.
Selvedge
The tightly-woven finished edge on either side of a woven fabric. Selvedges often carry the manufacturer's name and color dots; they shrink and pucker differently than the body of the fabric. Always remove selvedges before cutting binding strips.
Mitered corner
A method of turning a binding strip at a 90-degree corner by folding a small diagonal tuck before stitching the next side. Mitering creates a neat, flat corner and is the standard technique for square-corner quilts. Each miter consumes a small amount of extra binding length — one reason the calculator adds a buffer beyond the bare perimeter.
Straight-grain binding
Binding strips cut parallel to the fabric's warp or weft threads — either along the length of grain or across the grain (crosswise). Straightforward to cut and join; suitable for all straight-edged quilts. Compare to bias binding, which stretches to handle curves.
Bias binding
Binding strips cut at a 45-degree angle to the grain, which gives the strip stretch in both directions. Required for curved or scalloped edges; also drapes smoothly on straight edges. Uses significantly more fabric than straight-grain binding for the same finished length. This calculator does not cover bias binding.
Diagonal joining seam
The method of joining two binding strips end-to-end at a 45-degree angle rather than a straight seam. The diagonal distributes the bulk of the seam across a longer span, so the join lies flatter on the quilt's edge. Each join consumes a small extra amount of binding length, contributing to the need for a corner/join buffer.
Frequently asked
The calculation has four steps: find the perimeter (2 × (length + width)), add a buffer for corners and joins, divide by your usable fabric width and round up to whole strips, then multiply strip count by strip width to get total fabric in inches and divide by 36 for yards. The calculator above does all four steps instantly. The only inputs that require judgment are your WOF (measure after washing) and the corner/join buffer (10 inches minimum; more is safer for large quilts).
The most common cut width for double-fold binding is 2.5 inches, which finishes to approximately 3/8–1/2 inch on the quilt's edge. Some quilters prefer 2.25 inches for a narrower look; 2.75 inches is better for thick or lofty batting where you need more fabric to wrap cleanly to the back. The strip-width table on this page shows the approximate finished edge for each common width. When in doubt, cut a short test strip and wrap it around a layered scrap before cutting the full binding.
When you miter the binding at each corner, you fold extra fabric at a 45-degree angle, consuming more length than a straight run would suggest. Beyond that, joining your strips end-to-end with a diagonal seam uses a small amount of fabric at each join. With four corners and typically several joins on a bed quilt, a 10-inch buffer is a practical minimum — many experienced quilters use 12–15 inches. Running short by even a few inches near the end of a quilt is genuinely frustrating and can mean unpicking a corner you just mitered. A small buffer is cheap insurance.
WOF (width of fabric) is the usable width after selvedges are removed — the actual span across which you can cut a binding strip. Quilting cotton is typically printed on 44-inch bolts, but after washing and selvedge removal the usable WOF is usually 40–42 inches. The calculator divides your total binding length by WOF to find how many strips you need, so a smaller WOF means more strips and therefore more fabric. Using 42 inches is a safe conservative default; if you know your fabric runs narrower, adjust the input rather than discovering the shortage at the cutting mat.
Yes — bias binding is the right choice for curved or scalloped edges because the 45-degree cut gives the strip stretch, helping it lie flat around curves. For straight-edged quilts, straight-grain binding is the standard and uses less fabric. This calculator is built for straight-grain binding only. Bias binding requires cutting strips diagonally across a larger piece of fabric, and the yardage calculation is different enough that a separate tool is needed.
Double-fold binding (also called French-fold) is cut from a strip that is pressed in half lengthwise before being sewn to the quilt, so the finished binding has two layers. The double thickness hides the raw batting edge and wears well over time — it is the standard for most quilts. Single-fold binding uses a narrower strip folded just once and is thinner, less durable at the corners, and less common today. The strip widths in this calculator (2.25–2.75 inches) are calibrated for double-fold; single-fold requires different dimensions.
The arithmetic is exact for the numbers you enter — the page shows every formula and every step. Accuracy depends on the accuracy of your inputs. The two inputs that vary most in practice are WOF (measure your fabric after washing, not from the bolt label) and the corner/join buffer (10 inches is the minimum; your technique and quilt size may call for more). The strip count is always rounded up, so you will never end up with fewer strips than needed. As a further safety margin, buy the next eighth-yard increment above the calculator's result — the cost difference is minimal.
You cannot cut a fraction of a strip — you cut whole strips across the fabric width. If your total binding length is 290 inches and your WOF is 42 inches, you need 290 ÷ 42 = 6.905 strips; rounding down to 6 leaves you about 38 inches short. The calculator always rounds up (Math.ceil) to guarantee sufficiency. The trade-off is a short leftover strip, which is much better than running out of binding a few inches before the end of the quilt.
Common mistakes with this calculator
Binding is one of the last steps on a quilt — running short here is especially frustrating.
These are the inputs most likely to cause it.
Using bolt width instead of post-wash usable WOF
Quilting cotton is printed on 44-inch bolts but yields a usable WOF of roughly 40–42 inches after washing and selvage removal. Entering 44 instead of 42 can reduce the calculated strip count by one — and that missing strip means you run out of binding a few inches before the final corner. Measure your actual washed and trimmed fabric width before entering WOF.
Using the bare perimeter as the shopping number
The perimeter is the floor, not the ceiling. Mitered corners fold fabric diagonally and consume more length than a straight run; each joining seam adds a small additional amount. A buffer of at least 10 inches is the minimum; 12–15 inches is more comfortable on larger quilts. Quilters who buy exactly to the perimeter routinely run short in the last foot of binding.
Calculating from an unsquared quilt top
A quilt top that hasn't been squared and trimmed can measure several inches differently along opposite sides. Binding goes onto the finished, quilted, and trimmed sandwich — not the unsquared top. Calculating from an untrimmed measurement can overestimate or underestimate the actual perimeter by several inches in either direction.
Changing strip width without checking the finished edge
A narrower strip saves a small amount of fabric but also produces a narrower finished edge that can be harder to wrap cleanly over thick batting. Moving from 2.5-inch strips to 2.25-inch strips without first wrapping a test strip around a layered scrap is a common cause of binding that looks too thin on the finished quilt.