Cozy Stitchery

Blocks, Sashing & Borders Math

Finished size plus a quarter inch on every side

Maker
Quilt
Finished block size
Layout

Every piece in a quilt has two sizes. The finished size is what shows once it is sewn, and the unfinished or cut size is a half inch larger, because a standard quarter inch seam takes a quarter inch from each side. Plan in finished sizes, cut in unfinished sizes, and write both down so the two never get mixed up.

Layout worksheet

Center width is blocks across times block size, plus sashing strips between and around them. Add the border width twice for the finished quilt.

StepExample: throwYour quilt
Finished block size12 in
Blocks across5
Blocks down6
Blocks needed (across x down)30
Finished sashing width2 in
Center width (5 x 12 + 6 x 2)72 in
Center length (6 x 12 + 7 x 2)86 in
Finished border width4 in
Finished quilt width80 in
Finished quilt length94 in

That layout uses sashing around the outside edge as well as between blocks. Without the outer frame, use one fewer sashing strip in each direction.

Sashing, cornerstones and borders cut list

PieceHow manyCut sizeExample count and sizeYour quilt
Blocks, unfinishedAcross x downFinished + 1/2 in30 at 12 1/2 in square
Sashing strips(across + 1) x down + (down + 1) x acrossSash width + 1/2 by block + 1/271 at 2 1/2 x 12 1/2 in
Cornerstones(across + 1) x (down + 1)Sash width + 1/2 square42 at 2 1/2 in square
Side borders2Border + 1/2 by measured center length4 1/2 x 86 1/2 in
Top and bottom borders2Border + 1/2 by measured width with side borders on4 1/2 x 80 1/2 in

Measure borders through the center of the quilt, not along the edges, which stretch. Cut to the center measurement and ease the edge to fit, and the quilt will lie flat instead of rippling.

Half-square triangles and quarter-square triangles

Finished unitHST, 2 at a time: square to cutHST, 8 at a time: square to cutQST, 4 at a time: square to cut
2 in2 7/8 in5 3/4 in3 1/4 in
3 in3 7/8 in7 3/4 in4 1/4 in
4 in4 7/8 in9 3/4 in5 1/4 in
6 in6 7/8 in13 3/4 in7 1/4 in
FormulaFinished + 7/8 inFinished x 2 + 1 3/4 inFinished + 1 1/4 in

These are exact sizes. Many quilters add about 1/2 in and trim the unit down to unfinished size afterward, which forgives a wobbly seam. If you trim, write the trim size here too.

Flying geese

A flying geese unit is twice as wide as it is tall. The no-waste method makes four identical geese from one large square and four small squares.

Finished goose (W x H)No-waste: 1 large squareNo-waste: 4 small squaresStitch and flip: rectangleStitch and flip: 2 squares
2 x 1 in3 1/4 in1 7/8 in2 1/2 x 1 1/2 in1 1/2 in
3 x 1 1/2 in4 1/4 in2 3/8 in3 1/2 x 2 in2 in
4 x 2 in5 1/4 in2 7/8 in4 1/2 x 2 1/2 in2 1/2 in
6 x 3 in7 1/4 in3 7/8 in6 1/2 x 3 1/2 in3 1/2 in
FormulaW + 1 1/4 inH + 7/8 in(W + 1/2) x (H + 1/2)H + 1/2 in

On-point settings

ItemFormulaExample: 12 in blockYour block
Block diagonal (finished)Block x 1.41416.97 in
Side setting triangles, square to cut twice diagonallyBlock x 1.414 + 1 1/4 in18.22, cut 18 1/4 in
Corner triangles, square to cut once diagonallyBlock / 1.414 + 7/8 in9.36, cut 9 3/8 in

Cutting side setting triangles twice on the diagonal keeps the straight grain on the outside edge of the quilt, so the edge does not stretch.

Accurate cutting and a true quarter inch

Every number on this sheet assumes an accurate cut and a true quarter inch seam. A square-up ruler and a quarter inch foot protect both.

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