Calculate how many quilt blocks you need, fabric yardage per color, and cutting layouts — with seam allowance and sashing included
Finished size
Finished size
Finished block
Block fabrics
Blocks Across
Blocks Down
Total Blocks
Actual Size
finished quilt
Cutting guide
Cut block size:
Cut sashing strips:
Fabric yardage (42" WOF)
Fabric
Blocks
Sq. inches
Yards
Meters
Remember
Add 10-15% extra fabric for cutting mistakes and squaring up. For directional prints or fussy cutting, add 20-25% extra.
About This Tool
Planning a quilt? This calculator takes the math out of quilting. Enter your desired quilt size and block dimensions, and get exactly how many blocks you need, how much fabric to buy for each color, and a cutting guide for your rotary cutter.
Includes seam allowance (adjustable ¼" or custom), optional sashing and borders, and fabric yardage calculations based on standard fabric widths (42-44"). Supports multiple fabric colors with custom percentages, so you can plan scrappy quilts or precise two-color designs.
Perfect for beginners planning their first quilt or experienced quilters doing the math faster. Never buy too little fabric again.
How to Use
1. Enter your finished quilt size (width × length)
2. Enter your finished block size (after sewing)
3. Adjust seam allowance if needed (default ¼")
4. Optionally add sashing width between blocks
5. Add fabric colors and their percentages
6. See total blocks needed and fabric yardage per color
7. Check the cutting guide for strip/square sizes
Frequently Asked Questions
How do I calculate how many quilt blocks I need?
Divide your quilt width by the finished block size to get blocks across, then divide length by block size for rows. Multiply: blocks across × rows = total blocks. For a 60×80 inch quilt with 10-inch blocks: 6 across × 8 rows = 48 blocks. This calculator handles sashing and seams automatically.
What is seam allowance and why does it matter?
Seam allowance is the fabric between the stitching line and the raw edge — typically ¼ inch in quilting. You must add seam allowance to your cutting size. A 10-inch finished block needs 10.5-inch cut squares (adding ¼" on each side). This calculator adds it automatically.
How much fabric do I need for a quilt?
It depends on block size, quilt size, and how many colors. A rough rule: for a twin-size quilt (65×90"), plan 4-6 yards total. This calculator gives exact yardage based on your specific design, accounting for cutting waste and fabric width.
What is sashing in quilting?
Sashing is the fabric strips sewn between quilt blocks. It frames each block and adds size to the quilt. Common sashing widths are 1-3 inches finished. Sashing requires additional fabric — this calculator includes it in the yardage total.
What is standard quilting fabric width?
Quilting cotton is typically 42-45 inches wide (WOF = Width of Fabric). After removing selvages, usable width is about 40-42 inches. This calculator uses 42" as the standard and calculates how many cuts fit across the width.
How much extra fabric should I buy?
Buy 10-15% extra for cutting mistakes, squaring up, and shrinkage if you prewash. For directional prints or fussy cutting, buy 20-25% extra. This calculator shows the minimum needed — add your buffer on top.