Quilt Layout Calculator

12 inch block quilt layout reference chart

Finished quilt width equals columns multiplied by finished block size, plus interior sashing strips (columns minus 1) and twice the border width. Rows below show standard layouts built from 12 inch finished blocks, first plain and then framed with 2 inch sashing and a 4 inch outer border on 42 inch fabric.

Piece accurate rows with quilting rulers, cotton quilting thread, and 1/4 inch piecing feet.

Quilt layout FAQs

Do I enter finished or unfinished block size?

Enter the finished block size after sewing into the quilt top. A block cut or pieced to 12 1/2 inches unfinished measures 12 inches finished once its 1/4 inch seams are sewn.

Does sashing go around the outside of the blocks too?

This calculator places sashing between interior blocks only: columns minus 1 vertical sashing strips per row, and rows minus 1 horizontal sashing strips between rows. If you want a matching frame around the outer edge of the blocks, enter that width in the border field.

How is sashing yardage calculated?

Vertical sashing pieces are cut at block size plus 1/2 inch and sub-cut from 40 inch usable strips, while horizontal sashing strips span the full center width. Both strip counts are multiplied by sashing width plus 1/2 inch and rounded up to the next 1/8 yard.

Should I check the dedicated Backing Calculator for longarm overage?

Yes. The layout planner's optional backing toggle uses a compact 2 inch per side margin for quick budgeting, whereas longarm quilting generally requires 4 inches per side on the Backing and Batting Calculator.