Free Quilt Fabric Calculator
This quilt fabric calculator answers the four quilt math questions every quilter asks: quilt-top yardage, backing, binding, and squares per yard. Enter your quilt size once at the top and every section below uses it.
Quilt size
Usable width is the width after trimming the selvages. Quilting cotton is sold 42 to 44 in wide, and most quilters get 40 to 42 in of usable width. Sizes above are common defaults only: there is no single standard quilt size, so custom dimensions always work.
1. Quilt-top yardage
Piece-count method: cut size is finished size plus 1/2 in for two 1/4 in seams. If your quilt size is not an exact multiple of the block size, the finished quilt shrinks to the nearest multiple, and the page shows that actual size.
An area shortcut (quilt area times a factor) understates yardage when pieces are small, because it ignores strip-remainder waste.
2. Backing and batting
Backing seams use a 1/2 in allowance, so each seam consumes 1 in of width. Both layouts are computed and the smaller yardage is recommended. If you use a long-arm quilter, confirm their minimum overage before buying. Batting size equals backing size: trim after quilting.
3. Binding
Published join allowances run 10 to 20 in; 12 in is the default here and you can change it. Bias binding multiplies the straight-grain yardage by 1.5, the conservative published figure, because running short mid-binding is the failure mode. Published bias allowances range from 15 percent to 50 percent extra.
4. Squares, yardage and pre-cuts
Squares per yard uses a grid count, never area division: area division overstates what you can actually cut. A fat quarter is 18 x 22 in. A 9 x 21 in cut is a quarter-yard cut, not a fat quarter.
Total fabric to buy
Standard quilt sizes reference
If your quilt does not match a chart size, enter its exact size in the quilt fabric calculator above. Published charts disagree on every size, because mattress depth, side drop and pillow tuck all vary. Treat these as common defaults, not standards.
| Size | Common default | Published range |
|---|---|---|
| Baby | 36 x 52 in | 30 x 40 to 36 x 52 in |
| Throw | 50 x 65 in | 45 x 45 to 60 x 70 in |
| Twin | 70 x 90 in | 64 x 80 to 72 x 90 in |
| Full | 84 x 90 in | 76 x 87 to 85 x 108 in |
| Queen | 90 x 108 in | 88 x 92 to 96 x 108 in |
| King | 108 x 108 in | 104 x 92 to 110 x 108 in |
Pre-cut reference
| Pre-cut | Size | Count |
|---|---|---|
| Charm pack | 5 x 5 in squares | 42 per pack |
| Mini charm pack | 2.5 x 2.5 in squares | 40 or more per pack |
| Layer cake | 10 x 10 in squares | 42 per pack |
| Jelly roll | 2.5 in strips, full fabric width | 40 per roll |
| Fat quarter | 18 x 22 in | Sold singly or in bundles |
| Fat eighth | 9 x 22 in | Sold singly or in bundles |
Frequently asked questions
Why does this quilt fabric calculator give more yardage than an area estimate?
Because fabric is cut in strips, and the leftover strip ends cannot be reassembled into full pieces. The piece-count method counts real strips and real pieces, so it matches what you actually cut.
What is usable fabric width?
The width left after trimming the selvages. A 44 in bolt usually gives 42 in usable, and a 42 in bolt gives about 40 in. Enter your own measured width for exact results.
Do I need bias binding?
Only for curved or scalloped edges. Straight edges take straight-grain binding, which wastes less fabric. Bias binding is more durable under wear, which is why it is the choice for edges that curve.
Does this quilt fabric calculator cover borders?
Not in this version. Border yardage with multiple borders and mitered corners is a separate calculation. This page covers quilt-top yardage, backing, binding and squares.
How much extra backing do I need for long-arm quilting?
Long-arm quilters ask for 4 to 8 in per side. This page defaults to 4 in and offers 6 and 8 in. Confirm your quilter’s minimum before buying, since it varies.
See also: Free Online Calculators and Tools and Name Tracing Worksheets.