Pinwheel Quilt: How to Make a Pinwheel Block

IMG_1355The beauty of the Pinwheel Quilt is that it is so simple. There are only two kinds of squares in the pinwheel quilt — the pinwheel block, and the white square block. In this post, you’ll learn how to create the pinwheel block using a method that is easy and creates great results every time.

The pinwheel block is a classic quilt block made up of four half-square triangle blocks, also sometimes called HSTs. If you search the internet, you will find many different methods for making half square triangles, and I can tell you: I’ve tried all of them! They all work of course, but there is one method that I think consistently produces the best results. The method was developed by Jenny of Missouri Star Quilt Company, and involves sewing two fabric squares together and cutting them into fourths.

There are two main l reasons I like this method of creating HSTs:

  1. There is enough excess fabric such that you can square your blocks perfectly. Having perfectly square blocks is absolutely essential to ending up with perfect points and accurately sized pinwheel blocks.
  2. There is no need to mark your fabric prior to cutting or sewing. Yes, there are methods that can get you eight HSTs at once, but they involve drawing lines on your blocks, and when you have to create 105 blocks, it takes a lot of pencil sharpening and time, so it doesn’t actually save you time in the end.

To create your HSTs, follow these easy steps:

Step 1: Take one of each of your 5 inch squares and put them right sides together.
In this case, we are using solids, so there is no right or wrong side, but if you DO have a print, you’ll want to make sure it is facing in when you sew your block together.


Step 2: Sew a 1/4″ seam around the edge, putting your needle down and pivoting the fabric at each corner.



Step 3: Cut the square into fourths on the diagonal.


 Step 4: Iron your squares open.
Iron your fabric towards the pink triangles, or whichever fabric is darker.

Step 5: Square your blocks to 3″ each.
Place the ruler over your block and line up your block such that the corners are exactly on the diagonal of your HST, and you still have some excess on the other end (to be trimmed in the next step).

Rotate your block and trim the excess fabric, making sure that the corners of the block line up perfectly with the corners of the ruler.IMG_1333

Now that you have your HSTs, you can assemble your pinwheel blocks.


Step 1: Sew both pairs of HSTs together. Press the seam in opposite directions from each other.


Step 2: Sandwich the two HST pairs and sew together.


Step 3: Remove two to three stitches from seam in the middle and pull seam open so that it lays flat.




Step 5: Iron block flat and square your block to 5-1/2″. Starch block if desired. I starch my blocks because they hold their shape a little better.


NOTE: If you chain-piece your pinwheel squares, I recommend you stack your squares in piles that mimic the look of your finished block. There are two ways to assemble a pinwheel block, so it’s possible to assemble them incorrectly! And chain-piecing, while an efficient method of assembling blocks together quickly, is also an efficient method of quickly sewing things together incorrectly. Believe me, I’ve done this, and it’s no fun to have to rip out a bunch of mistakes!

That’s it! Now all you have to do is repeat this process 105 times. 🙂 Have fun!

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