Quilting Calculator — Fabric Yardage by Color & Block Layout

Paint each block cell with a fabric color, then get exact yardage per color with seam allowance already included. Export your layout as PNG or PDF. Runs entirely in your browser — nothing is uploaded.

Block & Quilt Settings

Cut size = finished size + 2× seam allowance. Yardage includes a 10% waste buffer, rounded up to nearest ⅛ yard.

Fabric Colors — click a swatch to select, then paint cells on the grid

Quilt Layout — click or drag to paint blocks

Fabric Yardage Required

Paint some blocks to see yardage.

How it works

Every quilt block needs a seam allowance on all four sides so pieces can be sewn together without cutting into the design. This calculator uses the standard quilting convention: add twice the seam allowance to each dimension to get the cut size.

Cut size per block Cut = Finished + 2 × Seam Allowance
e.g. 6" block + ¼" SA → 6.5" cut
Blocks per fabric row floor(WOF ÷ Cut size)
e.g. 44" ÷ 6.5" = 6 blocks/row
Fabric length needed ceil(Count ÷ Blocks/row) × Cut size
e.g. 18 blocks → 3 rows × 6.5" = 19.5"
Yards (with 10% buffer) (Length × 1.1) ÷ 36, rounded up to nearest ⅛ yd
19.5" × 1.1 = 21.45" → 0.625 yd = ⅝ yd

The 10% buffer accounts for pre-washing shrinkage, selvedge waste, and minor cutting errors — standard practice among quilting teachers and fabric shops.

Frequently asked questions

Why do I need to add seam allowance when calculating fabric yardage?
Quilt blocks are sewn together and the seam area is hidden inside the finished quilt. A standard ¼" seam allowance means each seam "consumes" ¼" on each piece. Because every block edge is a seam, you must cut each block ½" larger in both width and height (¼" per side × 2 sides). Without this allowance, your finished blocks would come out smaller than planned and may not align properly. This calculator adds the correct allowance automatically based on the seam size you select.
What is WOF and why does it matter for yardage?
WOF stands for Width of Fabric — the usable width after trimming the selvedge edges. Standard quilting cotton is sold in 44"–45" widths, but the actual printable/usable area is typically 42"–44". This calculator defaults to 44" WOF. Knowing the WOF lets us calculate how many blocks can be cut from a single horizontal strip, which determines how many strips (and therefore how many inches of fabric length) you need to purchase. If you use a wider fabric like 60" home-dec fabric, enter 58"–60" and yardage will decrease accordingly.
How does the per-cell color painting work?
Click or tap any cell in the grid to assign it the currently selected palette color (shown by the highlighted ring). You can also click and drag to paint multiple cells in one stroke. To change which color you're painting with, click any swatch in the Fabric Colors section. Unassigned cells are shown in dark gray and are excluded from yardage calculations. Use "Fill all" to paint every cell at once, or "Clear grid" to start over.
How accurate is the yardage estimate?
The estimate is accurate for simple square blocks cut straight on the grain. It assumes all blocks for a single color are cut from the same piece of fabric (no partial bolts). The 10% waste buffer covers selvedge trimming (~2"), pre-wash shrinkage (~1–2%), and minor cutting errors. For complex blocks with triangles, curves, or bias-cut pieces, you should add an additional 15–20% on top. Sashing, borders, binding, and backing are not included — they require separate yardage calculations.
What does "nearest ⅛ yard" mean and why does the calculator round to it?
Fabric shops cut fabric in increments of ⅛ yard (= 4.5 inches). You cannot purchase, say, 0.64 yards — the shop would cut either ⅝ yd (0.625) or ¾ yd (0.75). This calculator always rounds up to the next ⅛-yard increment so the amount you see is exactly what to ask for at the cutting counter: ⅛, ¼, ⅜, ½, ⅝, ¾, ⅞, or 1 yd, and so on.
Can I export the quilt layout to share or print?
Yes. Once you've painted your layout, use the "Download PNG" button to save a high-resolution image of the grid, or "Download PDF" to get a two-page PDF containing the layout diagram plus a fabric shopping list with yardage per color. The PDF is generated entirely in your browser using pdf-lib — no files are uploaded to any server.