When the measurements for enlarging the 6” block to a 12” block are placed into the equation: To work this out, use this simple equation:ĭesired enlarged Block size x 100 = resizing percentage In percentages, the size increase from 6” block to 12” block is 200%. from a 6” block to a 12” block, the area or space the block takes up is four times the area of the original block! Note: When a block is doubled in size, e.g. When the block is measured from raw edge to raw edge, its unfinished size (which includes seam allowances) will be 12 ½” x 12 ½”. So, to make a 12” finished nine-patch block, you will need to cut nine squares, each measuring 4 ½” x 4 ½” five squares in one colour and four in another. Now the seam allowances need to be added on: to enlarge from a 6” block to a 12” block, the finished size of the individual squares needs to be multiplied by two:Įach finished square will now measure 4” along each edge. To make the block twice as large the original, i.e. In the 6” square block, each identical square is 2” x 2” finished and that’s the measurement we will start with.

These blocks are standard, pieced quilt blocks, not foundation paper pieced.

The seam allowances are added on at a later stage.

When making calculations for enlarging or reducing a quilt block, you need to use the finished measurements.You can see the difference in the illustration below the dashed line indicates the seam allowances. The same block could also be described as 6 ½” x 6 ½” unfinished meaning that from raw edge to raw edge, the pieced quilt block measures 6 ½” square, including seam allowances.

The ¼” seam allowances around the outer edge of the block are not included in that measurement as they would’ve been sewn into the seams. This measures the quilt block as if it was assembled as part of a quilt. Quilt block sizes are usually described as finished e.g. We will be looking at four-patch, a grid of four squares in a 2 x 2 arrangement, two squares across, two squares down or nine-patch – a grid of nine squares in a 3 x 3 arrangement, three squares across, three squares down. Identify the layout or structure of the quilt block.We will be using simple blocks that include squares, half-square triangles and rectangles. Identify the different shapes that form the quilt block.Seam allowances are ¼” throughout and these will not be enlarged or reduced.

Quilt blocks