How to set a quilt on point

Turn the blocks 45° and fill the edges with triangles. A block's diagonal is block × 1.414; side triangles come from squares diagonal + 1¼″ cut twice; corners from squares block ÷ 1.414 + ⅞″ cut once. Choose your block and layout, then play the steps.

On-point layout simulator

Units Inches & yards Centimetres & metres

Finished block size

Blocks across the top edge

Blocks down the side

Try: 3 × 4 of 12″4 × 5 of 8″2 × 3 of 16″6 × 6 of 6″

▶ Play the steps ‹ Back Next ›

1. One blockFinished size, as the block looks upright.
2. Turn it 45°Now it is wider on the diagonal: block × 1.414.
3. Set the blocksRows of diamonds, with a second set in between.
4. Side trianglesFill each gap along the straight edges.
5. Corner trianglesFour small triangles finish the corners.

Step by step

1. Find the block diagonal = finished block × 1.414. A 12″ block: 17″.
2. Count the blocks. Blocks across × blocks down, plus the staggered set between them: (across − 1) × (down − 1). For 3 across and 4 down: 12 + 6 = 18 blocks.
3. Quilt centre size = across × diagonal by down × diagonal: 50 7/8″ × 67 7/8″ before borders.
4. Side triangles. Cut squares of diagonal + 1¼″ (18 1/4″), cut twice on both diagonals. 10 triangles need 3 squares.
5. Corner triangles. Cut 2 squares of block ÷ 1.414 + ⅞″ (9 3/8″), cut once on the diagonal. That is the four corners.
6. Sew in diagonal rows: corner triangle, block, side triangle, block… then join the rows.

Block size, diagonal and cut sizes

Count the pieces for your own layout with the setting triangle calculator. Formulas: how we calculate.

Questions quilters ask

What does it mean to set a quilt on point?

The blocks are turned 45 degrees so they sit as diamonds, with triangles filling the straight edges of the quilt. It makes a block look more dynamic and a small number of blocks go further, but it needs extra side and corner triangles.

How big is a block set on point?

Its corner-to-corner measurement is the block size times 1.414. A 12 inch block measures 17 inches across the diagonal, so three across take 50 7/8 inches.

How do you cut side setting triangles?

Cut a square the block's diagonal plus 1 1/4 inches (18 1/4 inches for a 12 inch block) and cut it twice on the diagonals to make 4 triangles. The long edge of each triangle goes on the outside, so the grain of the fabric runs along the quilt's edge and does not stretch.

How do you cut corner setting triangles?

Cut a square the block size divided by 1.414, plus 7/8 inch (9 3/8 inches for a 12 inch block) and cut it once on the diagonal to make 2 triangles. You need four corner triangles, so two squares.

Why are side triangles cut from a square cut twice?

Cutting twice puts the straight grain of the fabric along the long edge of each triangle, which is the edge on the outside of the quilt. Corner triangles are cut once for the same reason: their two short sides are on the straight grain and the long, bias edge goes against the blocks.

Keep learning

• Interactive How to calculate quilt backing Drag the quilt size and see the panels, the seams and the yardage change.
• Interactive How to calculate and make quilt binding Watch the strips get cut, joined at 45° and sewn around your quilt.
• Interactive How to make half-square triangles Pick a finished size and method: the cut size and every step, animated.
• Interactive What size quilt for a bed? Choose a mattress, a drop and a pillow tuck and see the quilt fall over the bed.
• Interactive How many squares from a fat quarter? See exactly how a fat quarter cuts up, and how much is left over.
• Free calculator Setting triangle calculator Just want the number? Type your size and get it straight away.

Updated 2026-11-14.