Sister's Choice Quilt Block — Cutting Chart for Any Size
2 fabrics · Difficulty 4 of 5
Sister's Choice is a 5×5 block of 33 pieces. Cut sizes for 5″, 7½″, 10″, 12½″, 15″, 17½″, 20″ are below; for any other size it divides into cleanly, type the size and the chart recomputes.
Set the finished sizeAt a glance
- Grid
- 5×5
- Pieces you cut
- 25 — subcutting turns them into the 33 in the sewn block
- Difficulty
- 4 of 5 — experienced How this is scored
Set the size
Nearest sizes that cut cleanly:
- Squares — Background
- 3″
- Squares — Fabric A
- 3″
- Squares for half-square triangles — Fabric A
- 3⅜″
- Squares for half-square triangles — Background
- 3⅜″
Reading focusCorner triangle outlines expose the lattice structurehalf-square-triangle unit
- Construction lattice
- 5 modules wide × 5 modules high
- Unit mix
- half-square-triangle unit, square
- Piece count
- 25 to cut · 33 in the diagram
Cut these pieces
Column headings are the FINISHED block size — the size it will be once it is sewn. Every number in the table is the size to CUT, which includes ¼″ of seam allowance on each edge. Rows that are subcut on a diagonal are cut larger still, so the allowance survives the extra cuts.
Scroll sideways to see every size.
| Patch | 5″ | 7½″ | 10″ | 12½″ | 15″ | 17½″ | 20″ |
|---|---|---|---|---|---|---|---|
| Squares — BackgroundCut 8 | 1½″ | 2″ | 2½″ | 3″ | 3½″ | 4″ | 4½″ |
| Squares — Fabric ACut 9 | 1½″ | 2″ | 2½″ | 3″ | 3½″ | 4″ | 4½″ |
| Squares for half-square triangles — Fabric ACut 4, cut once on the diagonal | 1⅞″ | 2⅜″ | 2⅞″ | 3⅜″ | 3⅞″ | 4⅜″ | 4⅞″ |
| Squares for half-square triangles — BackgroundCut 4, cut once on the diagonal | 1⅞″ | 2⅜″ | 2⅞″ | 3⅜″ | 3⅞″ | 4⅜″ | 4⅞″ |
Read the block
Match each fabric letter in the diagram to the same fabric name in the cutting table. The caption describes the generated geometry in text.
Fabrics in this block
- A — gold
- BG — background
Which sizes divide cleanly
Scroll sideways to see every column.
| Grid | Divides cleanly at | The first few sizes |
|---|---|---|
| 2×2 | every 1″ | 1″, 2″, 3″, 4″, 5″, 6″ … |
| 3×3 | every 1½″ | 1½″, 3″, 4½″, 6″, 7½″, 9″ … |
| 4×4 | every 2″ | 2″, 4″, 6″, 8″, 10″, 12″ … |
| 5×5this block | every 2½″ | 2½″, 5″, 7½″, 10″, 12½″, 15″ … |
| 7×7 | every 3½″ | 3½″, 7″, 10½″, 14″, 17½″, 21″ |
- A 5-patch block at 12″ would need 2.4″ units, which is not a mark on any ruler. Try 10″ or 12½″ instead — Sister's Choice is the 5-patch block on this site.
- A 7-patch block at 12″ would need 1.714…″ units, which is not a mark on any ruler. Try 10½″ or 14″ instead — Bear's Paw is the 7-patch block on this site.
More about the sizes that do not divide cleanly
The sizes in between
A 4″ Sister's Choice cannot be cut accurately on its 5×5 grid. Use 2½″ or 5″ instead. Enter either size above to compute its cutting chart.
Both columns are FINISHED block sizes — the size a block will be once it is sewn, never a size to cut. Look the clean size up in the charts on this page for its cutting numbers.
Scroll sideways if the table is wider than your screen.
| Size you want | Nearest sizes that cut cleanly |
|---|---|
| 4″ | 2½″ or 5″ |
| 6″ | 5″ or 7½″ |
| 7″ | 5″ or 7½″ |
| 8″ | 7½″ or 10″ |
| 9″ | 7½″ or 10″ |
| 11″ | 10″ or 12½″ |
| 12″ | 10″ or 12½″ |
| 13″ | 12½″ or 15″ |
| 14″ | 12½″ or 15″ |
| 16″ | 15″ or 17½″ |
| 17″ | 15″ or 17½″ |
| 18″ | 17½″ or 20″ |
| 19″ | 17½″ or 20″ |
About this block
- Pieces in the finished block
- 33
- Unit types
- half-square-triangle unit, square
- Divides cleanly at
- 2½″, 5″, 7½″, 10″, 12½″, 15″, 17½″ and 20″ finished.
- Attribution
- Ladies Art Company, about 1890 · Brackman #1802c
- Brackman number
- #1802c
- Fabric for one 12½″ block
- ½ yd total, rounded up to the nearest ⅛ yard, assuming 40″ of usable width.
More sizes fall between the ruler marks here than on most blocks — the side divides into an odd count of small modules — so read the clean-size table before cutting anything. Triangle units keep to the outer ring; the centre is plain squares throughout, which means the diagonals never reach the centre's own crossings.
Piecing order
Make the 8 half-square-triangle units.
Lay out row 1 of 5 and sew its pieces together, left to right.
Lay out row 2 of 5 and sew its pieces together, left to right.
Lay out row 3 of 5 and sew its pieces together, left to right.
Lay out row 4 of 5 and sew its pieces together, left to right.
Lay out row 5 of 5 and sew its pieces together, left to right.
Join the 5 rows, matching the seams.
How this site models this block
- This block's patch arrangement is still to be checked against Brackman's encyclopedia. Its 5×5 grid is what makes 12″ uncuttable here — 10″ and 12½″ are the nearest clean sizes — so the arrangement matters to the sizes, as well as the picture.
Cutting oversize
The chart gives the standard cut sizes, nothing padded. Some quilters cut this block's triangle units a little oversize and trim back — published allowances genuinely disagree on how much, so the range with its sources is on how to square up a quilt block.
History
Barbara Brackman records the name as a Ladies Art Company coinage of about 1890 and catalogues the block as #1802c. She returned to it in 2014, choosing it for the Austen Family Album block honouring Cassandra Austen — a sister's block for literature's most devoted sister. The five-patch geometry is the working fact on this page: a 5×5 lattice is exactly what decides which finished sizes cut cleanly and which this site refuses.
Sources: Barbara Brackman — Sister's Choice; Scissortail Quilting — Sister's Choice.
Common questions
What size can I make Sister's Choice?
Any size it divides cleanly: 2½″, 5″, 7½″, 10″, 12½″, 15″, 17½″ and 20″ finished. The chart above carries 5″, 7½″, 10″, 12½″, 15″, 17½″, 20″ ready-worked, and the size input computes any other clean size without you doing arithmetic — every value computed by Quilt Block Atlas, none transcribed.
How many pieces are in a Sister's Choice block?
33 pieces make up the sewn block, but you cut 25. The difference is method: triangle units are cut as squares and subcut, so the chart's quantities are what your rotary cutter produces, not what you count in the diagram.
What sizes does a 5×5 block divide into cleanly?
2½″, 5″, 7½″, 10″, 12½″, 15″, 17½″ and 20″ finished. The step is half the grid this block's cutting sizes are computed on, and the clean-size table above marks this block's row with the other families beside it.
Is Sister's Choice good for a beginner?
Not as a first block — it scores 4 of 5, experienced, on this site's computed scale: 33 pieces, with the half-square-triangle unit as its hardest unit. The scoring rule, and every block ranked by it, is on the difficulty page linked above.
How do finished size, sewn unfinished/trim size, and starting cut size differ?
Finished size is 12½″ after the block is sewn into surrounding seams. Its sewn unfinished/trim size is 13″ before those outer seams, derived with the plain-square allowance. Starting cut size is the method-specific input listed in the chart. Starting cut size equals the unfinished outer target only for a plain square or rectangle workflow; it is not generally the same for pieced triangle units.
Keep going
Related blocks
Where this block appears
Calculators for this block
- Quilt block grid calculator
- Half square triangle calculator
- Quilt top size calculator
- Fabric yardage calculator
Reference
Before you print
Measure this square before you cut. It must be exactly 1 inch. If it isn't, your printer scaled the page — reprint at 100% or "Actual size", not "Fit to page".