Start with the finished quilt top.
Measure your quilt top after it is complete. Backing and batting need extra room beyond the top so they can be secured for quilting.
Most quilting cotton is 44 to 45 inches wide, while wider backing fabric can reduce the number of seams you need.
Backing yardage at a glance
These are planning formulas for standard-width backing fabric. Always confirm the final requirements with your pattern or long-arm quilter.
| Quilt size | Planning formula | Example |
|---|---|---|
| Under 34 inches | Add 8 inches to the quilt measurement, then divide by 36. | A 28-inch square quilt needs 1 yard of 42-inch-wide backing. |
| 40 to 60 inches wide | Multiply the quilt width by 2, add 12 inches, then divide by 36. | A 47 by 74-inch quilt needs about 3 yards. |
| 61 to 80 inches wide | Multiply the quilt length by 2, add 12 inches, then divide by 36. | A 70 by 84-inch quilt needs 5 yards. |
| 81 to 120 inches wide | Multiply the quilt length by 3, add 18 inches, then divide by 36. | A 95 by 110-inch quilt needs 9 2/3 yards. |
Source: All People Quilt, “Plan Your Quilt Back and Determine Yardage”.
How much extra backing?
Plan for at least 8 extra inches in both directions. Some long-arm quilting guidance calls for 6 to 8 inches, so check with your quilter before ordering.
Sources: All People Quilt and Handi Quilter.
Binding estimate
Measure all four sides of the finished quilt and add at least 12 inches for corners and joining the binding ends.
Source: Sew4Home, “Binding Basics for Quilts, Blankets + Throws”.
Want the math done for you?
Use SewMe’s free calculator for a quick backing, binding, yardage, or project-cost estimate.
Sources and citation
Last updated September 2, 2026. This guide summarizes planning guidance from the sources below. Quilt patterns and long-arm quilters may require different allowances.
- All People Quilt, backing yardage planning guide
- Sew4Home, fabric-width and yardage planning guidance
- Sew4Home, binding calculation guidance
To cite this guide: SewMe, “Quilt Sizes, Backing & Yardage Guide,” updated September 2, 2026, shopsewme.com/quilt-size-guide.