Plan the whole quilt before you buy a yard: how many blocks, how the sashing and borders change the finished size, and the fabric for the top, backing, binding, and batting, each figure with its formula below.
Your Quilt
Fine-tune: fabric width and price
Your Quilt Plan
35blocks
5 across × 7 down · cut squares at 10.5 in
- Finished size as planned50 × 70 in (from 50 × 65)
- Fabric for the blocks2 ⅝ yd · 9 strips
- Sashing fabric:
- Border fabric:
- Backing (4 in overhang)3 ¼ yd
- Binding (2½ in strips)½ yd · 6 strips
- Batting that fitsTwin pack (72 × 90 in)
- Total fabric to buy6 ⅜ yd
- Estimated cost:
The block figure treats each block as a plain cut square, the planning floor. A pieced block pattern lists its own per-block cuts; add those instead once you’ve chosen one.
The Formulas, Part by Part
Blocks
blocks across = (width − 2 × border + sashing) ÷ (block + sashing), rounded · cut size = finished block + ½ inQuarter-inch seams on each side take half an inch from every cut square. The calculator rounds the block count to whole blocks, then reports the finished size that count really makes.
Fabric for the Blocks
squares per strip = ⌊usable width ÷ cut size⌋ · strips = ⌈blocks ÷ squares per strip⌉ · yards = strips × cut size ÷ 36Binding
binding length = perimeter + 12 in · strips = ⌈length ÷ usable width⌉ · yards = strips × 2½ ÷ 36The extra 12 inches pays for the four mitered corners and joining the ends. Backing follows its own seam-layout math, the backing calculator prices lengthwise, crosswise, and diagonal seams; the figure here uses the cheapest straight layout.
Worked Example
A 50 × 65 in throw from 10 in blocks, no sashing, no border, 42 in usable cotton:
- Blocks: 50 ÷ 10 = 5 across, 65 ÷ 10 = 6.5 → 7 down (rounded), so 35 blocks and a true finished size of 50 × 70 in.
- Cut squares at 10½ in: 4 fit a strip of 42 in fabric, 35 ÷ 4 → 9 strips × 10½ in = 94½ in → 2⅝ yd for the blocks.
- Binding: perimeter 240 + 12 = 252 in → 6 strips → 6 × 2½ = 15 in → ½ yd.
- Backing at 4 in overhang (58 × 78): 2 crosswise widths → 3¼ yd. Batting: a twin pack covers it.
Quilt Fabric Chart by Bed Size
Computed by the calculator above: 10 in plain blocks, no sashing or border, 42 in usable cotton, binding in 2½ in strips, backing at 4 in overhang.
| Quilt | Blocks (10″) | Block fabric | Backing | Binding | Total |
|---|---|---|---|---|---|
| Crib 36×52 | 20 (4×5) | 1 ½ yd | 2 ¾ yd | ⅜ yd | 4 ⅝ yd |
| Throw 50×65 | 35 (5×7) | 2 ⅝ yd | 3 ¼ yd | ½ yd | 6 ⅜ yd |
| Twin 70×90 | 63 (7×9) | 4 ¾ yd | 5 ½ yd | ⅝ yd | 10 ⅞ yd |
| Full 84×90 | 72 (8×9) | 5 ¼ yd | 7 ⅜ yd | ⅝ yd | 13 ¼ yd |
| Queen 90×100 | 90 (9×10) | 6 ¾ yd | 8 ¼ yd | ¾ yd | 15 ¾ yd |
| King 108×108 | 121 (11×11) | 9 ⅛ yd | 9 ⅞ yd | ⅞ yd | 19 ⅞ yd |
How to Measure and Choose Your Inputs
- Quilt size: for a bed, measure mattress top, then add drop on three sides and tuck if you want one. The presets use common finished-quilt sizes; a coverlet and a full drop differ by a foot.
- Block size means finished: sewn into the quilt. A charm pack’s 5 in squares finish at 4½.
- Sashing and border are finished widths too. The calculator adds the seam allowances back when it figures the cut strips.
Assumptions and Defaults
- Seam allowance is the quilter’s ¼ in everywhere, so every cut adds ½ in to a finished measurement.
- Yardage rounds up to the next ⅛ yard, part by part: buying is by the part, so each part rounds alone.
- Binding is cut cross-grain at 2½ in, the double-fold standard. Bias binding takes about a quarter more.
- Backing uses the cheapest straight seam layout at 4 in overhang; wide backs and the diagonal method live in the backing calculator.
- Nothing here includes shrinkage. Prewashing? Add about 5% per part.
Quilt Planning Questions, Answered
How much fabric do I need for a quilt?
A quilt needs fabric for three parts: the top, the backing, and the binding. A 50 × 65 in throw takes about 2⅝ yd of block fabric, 3¼ yd of backing, and ½ yd of binding, or 6⅜ yards in all before a pattern adds piecing, and the chart above carries the same figures through king size.
How many blocks do I need for my quilt?
The number of quilt blocks is the quilt width ÷ the finished block size across and the length ÷ the block size down, both rounded to whole blocks. Sashing stretches each repeat, so 10 in blocks with 2 in sashing repeat every 12 in, and the calculator reports the finished size your rounded count actually makes.
What seam allowance is used for quilting?
Quilting uses a ¼ in seam allowance, and most piecers sew a scant quarter, about a thread narrower, so the pressed seam’s fold keeps the full width. The ⅝ in allowance from garment sewing is far too wide for piecing.
What size should my quilt be?
Common finished quilt sizes are 36 × 52 in for a crib, 50 × 65 for a throw, 70 × 90 for a twin, 84 × 90 for a full, 90 × 100 for a queen, and 108 × 108 for a king. For a made bed, measure the mattress and add 10 to 15 in of drop on each open side, plus a pillow tuck if you want one.
How much is a handmade quilt worth?
A handmade quilt is worth its materials, about $100 to $300 at the yardages above, plus the labor, which is the larger share, plus longarm quilting billed by the square inch. A fair price adds materials, hours at a real rate, and quilting fees, and the quilt pricing calculator walks through the whole sum.
Does the quilt calculator handle pieced blocks like log cabins or stars?
Yes, the quilt calculator plans the quilt around pieced blocks, covering the count, layout, backing, binding, and batting, while it prices the blocks as plain squares, the baseline any pattern builds on. Cutting for specific units such as flying geese, HSTs, and hexagons belongs to each block calculator, and those go into more detail.