Calculator
Quilt Sashing Calculator
How much sashing fabric for any quilt grid. Reference table for 12″ blocks at common sashing widths.
Sashing Yardage — 12″ Blocks
| Grid (rows×cols) | 1.5″ sashing | 2″ sashing | 2.5″ sashing | 3″ sashing |
|---|---|---|---|---|
| 3×4 (Baby) | ~0.7 yds | ~0.8999999999999999 yds | ~1.2 yds | ~1.4 yds |
| 4×5 (Throw) | ~1 yds | ~1.3 yds | ~1.7 yds | ~2 yds |
| 5×7 (Twin) | ~1.5999999999999999 yds | ~2.1 yds | ~2.6 yds | ~3.2 yds |
| 6×8 (Queen) | ~2 yds | ~2.7 yds | ~3.4000000000000004 yds | ~4.2 yds |
| 7×8 (King) | ~2.3000000000000003 yds | ~3 yds | ~3.9000000000000004 yds | ~4.8 yds |
Estimates include 10% safety margin. For cornerstones, add 0.25 yds of cornerstone fabric.
Sashing Formula
- 1. Count horizontal strips: (rows + 1) strips, each as long as the quilt width.
- 2. Count vertical strips: (cols + 1) strips, each as tall as the quilt height.
- 3. Calculate total area: Total strip area = (all strip lengths × sashing width in inches).
- 4. Convert to yards: Divide by 1,296 (36″ × 36″). Add 10% safety margin.
Cornerstones
Cornerstones are small squares at sashing intersections. For a grid of R rows × C columns, you need (R+1) × (C+1) cornerstone squares, each cut at (sashing width + 1/2″).
| Grid | Cornerstones needed | Cut size (2″ sash) |
|---|---|---|
| 3×4 (Baby) | 20 | 2-1/2″ squares |
| 4×5 (Throw) | 30 | 2-1/2″ squares |
| 5×7 (Twin) | 48 | 2-1/2″ squares |
| 6×8 (Queen) | 63 | 2-1/2″ squares |
| 7×8 (King) | 72 | 2-1/2″ squares |
Frequently Asked Questions
How much fabric do I need for quilt sashing?
For a queen-size quilt (6×8 grid of 12-inch blocks) with 2-inch sashing, you need approximately 1.5–2 yards of sashing fabric. The exact amount depends on the grid size, block size, and sashing width. Always add 10% for cutting waste.
What are cornerstones in a quilt?
Cornerstones are small squares placed at the intersections where sashing strips meet. In a grid with cornerstones, each intersection has a contrasting square rather than a continuous sashing strip. Cornerstones add a secondary design element and are a great use for a bold accent fabric.
How wide should quilt sashing be?
Sashing width is a design choice. Common widths: 1.5" (narrow, emphasizes blocks), 2" (balanced, most common), 2.5" (moderately open), 3–4" (wide, airy feel, great for showcasing quilting stitches). Very wide sashing can make a quilt look like a sampler.
Can sashing change the final quilt size?
Yes, significantly. Adding 2" sashing between blocks in a 6×8 queen layout adds approximately 14" to the width and 18" to the height. Sashing is a common tool for making a quilt larger without making more blocks.