Quilting calculator
Quarter-Square Triangle Calculator
Size starting squares and batches for classic two-color quarter-square triangle units.
Free · No account · Editable assumptions
Your result
Recommended answer Calculated resultA value derived from the same validated inputs, assumptions, and calculation contract shown on this page.Learn more
Copies a concise text summary of the current result when browser clipboard access is available.Opens the browser print flow using the dedicated readable plan layout.Transfers the compatible calculated cut requirement into the locally saved project for joint planning.
How this calculator works
Assumptions
This models a classic two-color hourglass/QST batch. Each batch starts with two squares from each fabric and makes four units. It does not cover every multi-color QST construction variation.
Methodology
Standard starting squares add 1¼ inches to finished size; trim-friendly squares add 1½ inches. Batch count rounds upward, so produced and excess units remain visible.
Worked example
For 24 finished 4-inch QSTs in trim-friendly mode, cut twelve 5½-inch starting squares from each fabric. Six batches produce exactly 24 units, trimmed to 4½ inches unfinished.
Limitations
This focused calculator covers the construction method and rectangular measurements described above. It does not infer a complete quilt pattern or replace method-specific instructions.
Common question
Can I change the defaults? Yes. The visible defaults are planning conveniences; use the measurements and assumptions that match your fabric, method, and quilting setup.
Keep planning
Plan more than one piece
Combine all the rectangles for each fabric into a shopping list, cutting list, and visual layout.
Open the fabric cutting plannerTransfers the compatible calculated cut requirement into the locally saved project for joint planning.