Quilt block diagram

Pinwheel quilt block

Four half-square-triangle units rotate around the center to form a clean spinning shape.

Block structure

How the geometry is organized

A 2 × 2 grid in which every square is divided diagonally and the darker triangles rotate in one direction.

  1. 1Make four matching half-square-triangle units with your preferred method.
  2. 2Rotate the colored triangle one quarter-turn in each position.
  3. 3Join two rows, then align the center intersection.
Repeat this block

Finished-size planning

Basic unit sizes

These values divide the finished block evenly for drawing and layout. They do not include seam allowance or method-specific trimming.

6 in block3 in unit
8 in block4 in unit
9 in block4.50 in unit
10 in block5 in unit
12 in block6 in unit