How to Calculate Fabric Yardage for a Quilt
A complete guide to calculating fabric for every component of a quilt — from blocks to backing.
The Five Components of a Quilt
Every quilt is made up of distinct fabric components, each of which needs its own yardage calculation. A complete quilt typically includes:
- Quilt top blocks — the pieced or appliquéd design
- Sashing — strips between blocks (optional)
- Borders — framing strips around the quilt edge (optional)
- Backing — the fabric layer on the back of the quilt
- Binding — the strip that finishes the raw edge
Calculate each component separately, then add them together. Trying to estimate the whole quilt in one step leads to errors.
The Basic Yardage Formula
For any quilt component, the process is the same:
- Calculate total area needed (in square inches): multiply the piece dimensions by the number of pieces
- Determine how many strips you can cut: divide piece height into your fabric width (use 40″ as a safe usable width)
- Calculate total strip length needed: divide total area by usable fabric width
- Convert to yards: divide total inches by 36
- Add waste factor: multiply by 1.10–1.15 (10–15% buffer)
Calculating Block Fabric
Most quilt blocks require multiple fabric pieces. Calculate each unique fabric separately.
Worked example: You are making 30 twelve-inch blocks. Each block uses eight 3.5″ × 3.5″ squares of Background Fabric A.
Total squares needed: 30 blocks × 8 squares = 240 squares
Squares per strip (from 40″ fabric): 40 ÷ 3.5 = 11 squares per strip (round down)
Total strips needed: 240 ÷ 11 = 21.8 → 22 strips
Total fabric needed: 22 strips × 3.5″ = 77″
In yards: 77 ÷ 36 = 2.14 yds
With 10% waste: 2.14 × 1.10 = 2.35 yds → buy 2.5 yds
Calculating Sashing Fabric
Sashing runs between blocks and often around the perimeter of the block layout. For a quilt with a 5×6 block arrangement using 2″ sashing:
Horizontal sashing strips: 5 columns × 7 rows (blocks + 1) = 35 strips
Vertical sashing strips: 6 rows × 6 (blocks + 1) = 36 strips
Each strip length = block size + seam allowances = 12″ + 0.5″ = 12.5″
Strips per yard of fabric (at 2″ wide): 40 ÷ 2 = 20 strips
Total strips: 35 + 36 = 71 strips
Yards needed: 71 ÷ 20 = 3.55 yds
With 10% waste: 3.9 yds → buy 4 yds
Calculating Border Fabric
Borders are calculated by their total perimeter length and width. The trick is to measure after accounting for any sashing already added.
Important: Always measure borders by cutting strips the exact length of the quilt, not the length of the border strip. Measure through the center of the quilt, not along the edges, to prevent wavy borders.
Example: 4″ border on a quilt that is 70″ × 85″
Top + bottom strips: 2 × 70″ = 140″
Side strips (add border width × 2): 2 × (85″ + 8″) = 186″
Total border length: 140″ + 186″ = 326″
Strips per yard (at 4″ wide): 40 ÷ 4 = 10 strips per yard of fabric
Strips needed: 326 ÷ 40 = 8.15 → 9 strips
Yards: 9 strips × 4″ ÷ 36 = 1.0 yd
With 10% waste: 1.1 yds → buy 1.25 yds
Calculating Backing Fabric
Backing is usually the single largest yardage purchase. Add 4–6 inches to each dimension of your quilt top for overhang, then calculate how many panels of fabric width you need.
Quilt top: 70″ × 85″, add 6″ per side → Backing needed: 82″ × 97″
Using 44″ wide fabric (40″ usable): 82 ÷ 40 = 2.05 → need 3 panels
Each panel length: 97″
Total fabric: 3 × 97″ = 291″
In yards: 291 ÷ 36 = 8.1 yds → buy 8.5 yds
Alternatively, 108″ wide backing fabric would need only: 97″ ÷ 36 = 2.7 yds → buy 3 yds. Wide backing saves significant yardage for large quilts.
Calculating Binding Fabric
Binding is the simplest calculation. Add up the quilt perimeter, add 12″ for joining and corners, then calculate strips needed:
Perimeter: 2 × (70 + 85) = 310″
Add 12″ buffer: 322″ total
Strips from 40″ fabric: 322 ÷ 40 = 8.05 → 9 strips
Yardage: 9 × 2.5″ ÷ 36 = 0.63 yds → buy ¾ yd
The 10% Rule — Why You Should Always Buy More
Every fabric calculation above includes a 10–15% waste factor. Here is why this matters in practice:
- Pre-wash shrinkage: Cotton fabric shrinks 3–5% when washed. If you pre-wash (recommended for bed quilts), factor this in.
- Cutting errors: A slightly off-grain cut, a slipped ruler, or a miscalculation means wasted fabric.
- Pattern matching: Directional prints and large repeats require extra fabric to align patterns across cuts.
- Dye lot changes: If you run short and go back for more, the new fabric may be a slightly different shade.
- Future repairs: Keeping a small remnant lets you repair the quilt if it is ever damaged.
The cost of buying an extra ¼ to ½ yard is small compared to the cost of running short mid-project. Round up to the nearest ¼ yard on every calculation.
Complete Project Example: Queen Quilt
| Component | Calculated | Buy |
|---|---|---|
| Background fabric (blocks) | 3.2 yds | 3.5 yds |
| Accent fabric (blocks) | 2.8 yds | 3 yds |
| Sashing | 1.6 yds | 1.75 yds |
| Border | 1.1 yds | 1.25 yds |
| Backing (44″ wide) | 8.1 yds | 8.5 yds |
| Binding | 0.7 yds | 0.75 yds |
| Total fabric cost | 17.5 yds | 18.75 yds |
Let the Calculator Do the Math
Enter your quilt dimensions, block size, sashing, and border details to get an instant breakdown of yardage for every fabric in your project — with waste factor built in.
Use the Free Fabric Yardage Calculator →For backing yardage specifically, see our fabric width reference to understand how choosing 44″ vs 108″ wide fabric changes your yardage needs.