Grow-a-Quilt 2021 – Step 5 – Pinwheel Block

You decide:

  • What size of block do you want?  Pinwheel Blocks are made of 4 Half Square Triangles (HSTs) and the block finishes at 2 times the size of one of the finished HSTs.  For example, if you want to add 5” to your quilt then you would need 4 HSTs that are 2.5” finished size (3” unfinished size). 
  • How many do you want?  Do you want the Pinwheels to go all around the row or do you want to combine it with strips, single HSTs, or other blocks such as Dot Blocks. 
  • Think about the background.  If you want it all the same, you will need enough to make all your blocks.
  • Do you need spacers between the blocks to make them fit the side on which you are growing your quilt?
  • Hint: When measuring the length of a side, measure at the centre as well as the edge.  If the centre is narrower, make the next row to its measurement.  This helps keep the quilt square.


  • Each Pinwheel requires 4 HSTs.  They are assembled in a four-patch as in the photo.
  • There are several ways to make HSTs.  The most popular is to make two at one time.  In the links, I included a method for making 8 HSTs at one time.
  • If making the Magic 8, then an 8” square yields four 3” finished HSTs, a 7” square yields four 2.5” HSTs trimmed.
  • For members looking for a more challenging block, have a look for the Double Pinwheel.

Helpful Links:

Happy Quilting,
Marilyn and Barb


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