Patch & MeasureA little less math. A little more making.
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01 / PLAN YOUR BACKING

Quilt backing calculator.

Calculate quilt backing yardage, compare horizontal and vertical panels, and plan batting dimensions in inches or centimeters.

Example project
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Your measurements

1 Quilt top
Actual quilt-top width.
Actual quilt-top length.

Use decimals or fractions, such as 60 1/2.

2 Backing fabric
Width after removing selvages.
Confirm with your longarm quilter.
Try a width
On each joined edge; not per seam.
For batting dimensions only.
One-way print? Select the direction that keeps the fabric upright. This does not match pattern repeats.
3 Fabric to buy

We round up once, at the end. Add more if you need extra for shrinkage or squaring the fabric.

Plan binding with these dimensions →

A little room to be sure: check the measurements and assumptions before buying or cutting.

THE MATH, UNPACKED

A good backing starts
with a little breathing room.

The backing needs to extend beyond your quilt top. The calculator adds your chosen overage on every side, then compares full-width fabric panels in two orientations.

Read the full method →
How is the fabric calculated?

For each layout, the sewn coverage is the total panel width minus two seam allowances for every join. Each full-width panel is cut to the required backing length in that orientation. The panel lengths are added and the purchase is rounded up.

A 60 × 80 inch example

With 4 inches extra per side, 42 inches of usable fabric width and 1/2-inch seam allowances, vertical piecing needs two 88-inch lengths: 176 inches of fabric. Rounded up to the next 1/8 yard, buy 5 yards. Horizontal piecing needs three 68-inch lengths, or 5 3/4 yards after rounding.

What is outside this estimate?

Print matching, shrinkage, trimming each panel square, diagonal backing, and layouts assembled from smaller offcuts are not included. The lowest-yardage layout is only the lowest among the two full-panel layouts compared here.