How Many 8-inch Blocks for a King Quilt?

Planning a King Quilt with 8-inch Blocks

A King quilt typically measures 108 × 108 inches finished —fits a standard king mattress with generous drops on all sides. Using 8-inch finished blocks with 2-inch sashing and a 3-inch border, you will need 100 blocks arranged in a 10 × 10 grid.

If you prefer a simpler layout without sashing — blocks set edge to edge — the same King quilt needs 169 blocks in a 13 × 13 arrangement, finishing at approximately104″ × 104″.

Choosing Your Sashing Width

Sashing frames individual blocks and brings the quilt top to the desired finished size with fewer blocks. Wider sashing (3–4 inches) gives a more open, airy feel; narrower sashing (1–1.5 inches) lets the blocks be the star. No sashing at all creates a seamless all-over pattern — especially effective with blocks that form continuous secondary designs when set edge to edge, like Pinwheel, Nine Patch, and Flying Geese.

Calculating Fabric for a King Quilt

The fabric estimates above assume two fabrics per block, standard 44-inch quilting cotton, and a seam allowance of ¼ inch. In practice, quilts made from many different scrappy fabrics will need different yardages for each fabric. Add 10–15% to all estimates to account for cutting waste, miscuts, and design changes.

For the backing, you will need the quilt top dimensions plus 4 inches on all sides. A King quilt top of approximately 104″ × 104″ needs a backing of at least 112″ × 112″. For quilts wider than 44 inches, backing fabric must be pieced or wide backing fabric (108 inches wide) used.