How to Calculate Quilt Binding Yardage

Binding yardage starts with the finished quilt perimeter, not the quilt area. Add the join allowance, decide the finished binding width, and then calculate how many strips can be cut across the usable fabric width. Bias and straight-grain binding follow the same length arithmetic but may need different cutting directions.

Find the binding length

For a rectangular quilt, perimeter is 2 × (finished width + finished length). Add a join allowance for every seam and a tail allowance at the beginning and end. If the quilt is 60 by 80 inches, the perimeter is 280 inches. Add 20 inches for joins and 8 inches for tails: 308 inches total, or 8.556 yards of continuous strip length.

Choose the cut-strip width from the finished binding width and the fold method. A 2.5-inch double-fold strip is common, but the pattern or binding method controls. If the fabric has 42 inches of usable width, floor(42 ÷ 2.5) = 16 strips fit across one crosscut. Sixteen strips from a 42-inch crosscut provide 672 inches of strip length before selvage loss, so one crosscut is enough for the example only if the grain direction and cut plan permit it.

Worked example

For a 60-by-80-inch quilt, use 2.5-inch strips, 42-inch usable width, 20 inches of join allowance, and 8 inches of tails. Required length is 308 inches. One crosswise cut across a 42-inch width provides 16 strips, each about 42 inches long, for 672 inches before edge trimming. That creates substantial leftover strip length, but the strips may not be legal if the fabric is directional or if the binding must be bias cut for curves.

If the same project uses a 44-inch usable width and you reserve 1 inch at each selvage, the calculation is based on 42 inches, not the nominal 44. Keep the reserve visible. A small change in usable width rarely changes the strip count, but it can matter when the pattern repeat or damaged edge consumes a row.

Verification checklist

• Measure the finished quilt after borders are attached.
• Add join and tail allowances explicitly.
• Record finished binding width and cut-strip width.
• Confirm whether bias or straight grain is required.
• Use usable width after selvage and defects are excluded.
• Check whether the strip can rotate without violating grain or motif rules.
• Keep extra strips for testing and repairs when the fabric is limited.

Caution

Binding length is not automatically binding yardage. A fabric with nap, a one-way print, or a strong plaid can require a different cutting direction and more yardage. Make a paper layout when the strip plan is close to the edge of the bolt.

Sources and derivation

Use the seam and hem allowance reference and the bias binding calculator to check perimeter, strip width, and join loss. Compare with continuous bias binding yardage before cutting.