How much fabric do I need to back a twin size quilt?

For a twin quilt top around 70x90 inches with a standard 4 inch overhang per side, you'll need roughly 5.75 yards of standard 44 inch quilting cotton (pieced into 2 panels), or about 2.75 yards of 108 inch wide backing fabric (a single panel, no piecing).

How Much Fabric for a Twin Size Quilt Backing?

For a twin quilt top around 70″ × 90″, plan on roughly 5 3/4 yards of standard 44″ quilting cotton, or about 2 3/4 yards of 108″ wide backing fabric. As always, the exact number depends on your quilt's actual finished size and overhang, so run your specific dimensions through the quilt backing calculator rather than relying on a rule of thumb alone.

Why twin backing still needs piecing

A twin quilt is narrower than a queen or king, but at 70″ wide (78″ once you add a 4″ overhang on each side) it's still wider than a single width of standard 44″ fabric, which has only about 40″ of usable width after trimming the selvages. That means a standard-width backing still needs two panels seamed together, even though the quilt itself is on the smaller side.

108″ wide backing fabric comfortably covers a twin backing's 78″ width in a single piece, which is why the wide-backing yardage is so much lower here, and why there's no piecing seam to quilt around.

Twin quilts vary more than queen or king

Twin quilt patterns vary more in finished size than queen or king does: some run closer to 64″ × 84″, others closer to 70″ × 90″ or larger for a "twin XL" sized to fit a dorm bed. That's a meaningful swing in total yardage at this size, more so than at queen or king where patterns tend to cluster closer together, so it's worth double-checking your specific pattern's finished dimensions rather than assuming a generic twin number applies.