Quilt block diagram

Square-in-a-square quilt block

A square set on point sits inside four corner triangles, giving a crisp diamond without a curved seam.

Block structure

How the geometry is organized

One centered diamond whose points meet the midpoint of every block edge.

  1. 1Mark the midpoint of each finished edge.
  2. 2Center the inner square on point.
  3. 3Surround it with four corner triangles, preserving the outer square.
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