Make 9 Patch and 16 Patch Quilt Blocks Any Size with No Math - Finished-Size Quilting

Check out the animation below, showing how easy it is to
make 9-patch blocks any size you want.

Then, scroll down to see how you can make
16-patch blocks just as easily.

Seam Allowance Additions
automatically add the exact seam allowances:  

Color-Coded Quilt Block Breakdowns

show what traditional blocks are made of and how the
pieces go together. They show all the squares in purple, half
square triangles in green and quarter square triangles in red.

9-Patch Blocks

16-Patch Blocks

Pick any finished size and attach the:

  • Purple S Addition for the squares
  • Green H Addition for the half square triangles
  • Red Q Addition for the quarter square triangles

Click on the button below to download an 8-page Seam Allowance Aditions booklet that includes the Breakdowns below:

Click here for set options with 1, 2 or 3 Guidelines Rulers.

Click here for set options that you can use with regular 12" & 24" rulers you already have.


Let's Make a 9-Patch Block First:

This Double Friendship Star is made of nine patches.
5 patches are just Squares and the other 4 are a combination of
Half and Quarter Square Triangles sewn together:

The color-coded breakdown also shows how many
of each piece you will need to make all nine patches:

5 Squares

4 HSTs

8 QSTs

Click the headings below to open. - Click again to close.

What size block do you want to make?

6" Block

9" Block

12" Block

The finished patch size is all you need to make the entire block:

Finished patch size: 2"

Finished patch size: 3"

Finished patch size: 4"

These are common finished sizes for 9-patch blocks like this Double Friendship Star,
but you can pick any size you want.

In Finished-Size Quilting, you can make any 9-patch block finish at 9" using just the 3" line on your ruler.

Finished sizes are that simple:

3" + 3" + 3" = 9"

Simply set the Fabric Guide to the finished patch size: 3”, and let the Seam Allowance Additions automatically add the precise amount of seam allowance for you.

The seam allowance is automatically included when you cut along the edge of the Addition instead of the edge of the ruler.

Seam Allowance Additions not only eliminate the complicated seam allowance math, they also let you make your triangles more accurate than you can using just a ruler alone. *

Click here to learn more about seam allowances for triangles.

The S Addition adds a 1/2", which is the exact amount you need for Squares.

Cut five squares.

The H and Q Additons add the precise amount for Half and Quarter Square Triangles. *On a ruler alone, you have to round up to the nearest 1/8" making your triangles less accurate.

Cut two squares &
cut them once diagonally.

Cut two squares &
cut them twice diagonally.

Your Squares, Half and Quarter Square Triangles
will automatically include 1/4" seam allowances all around.

After sewing the pieces together, your block will measure 9 1/2".

(9" finished with a 1/4" seam allowance all around.)

You’ll always have the extra 1/4” you need to sew the pieces, rows and blocks together.

Now Let's Make a 16-Patch Block:

This Royal Star is made of 16 patches.
Four patches are just Squares, four are a combination of Half Square Triangles sewn together and eight are a combination of Quarter Square Triangles sewn together:

The color-coded breakdown also shows how many of
each piece you will need to make all sixteen patches:

4 Squares

8 HSTs

32 QSTs

Click the headings below to open. - Click again to close.

What size block do you want to make?

8" Block

12" Block

16" Block

The finished patch size is all you need to make the entire block:

Finished patch size: 2"

Finished patch size: 3"

Finished patch size: 4"

These are common finished sizes for 16-patch blocks like this Royal Star,
but you can pick any size you want. Click on the heading below to see how:

You can make common sizes by lining up to the 2", 3" or 4" line.
But what if you wanted to make it finish at 9 inches?

Using a ruler alone, making a 16-patch block finish at 9" would be a math nightmare.

In Finished-Size Quilting,
you only need to know the Finished Patch Size:

Click on the heading below to see how simple it is
to make a 16-patch block that finishes at 9":

The S Addition adds a 1/2", which is the exact amount you need for Squares.

Cut five squares.

The H and Q Additons add the precise amount for Half and Quarter Square Triangles. *On a ruler alone, you have to round up to the nearest 1/8" making your triangles less accurate. Click here to learn more.

Cut four squares.

Cut eight squares.

Cut the squares into triangles first or sew the seams first?  

When you're making patches that are combinations of just Half Square Triangles or just Quarter Square Triangles as in this Royal Star block, you have the choice of cutting the squares into triangles first or sewing the seams first and then cutting them into triangles. See details in the next section.

You can either sew first or cut first to make patches made of
HSTs & QSTs in blocks like the Royal Star below:

2 Half Square Triangle-Patch

4 Quarter Square Triangle-Patch

Sew First Method:

How to Make the 2 HST Patches

Line the squares up and sew the diagonal seams first:

How to Make the 4 QST Patches

Start the same way as we showed to make 2 HST patches:

Then, repeat the steps above,

starting with the two new squares you just made:

Cut First Method:

Cut the squares that you made, using the H Addition, in half diagonally once to make eight half square triangles.

Cut Quarter Square Triangles:

First, attach the Q Addition to the edge of the Ruler.

Leave the Fabric Guide set on 2 ¼" line & cut 8 squares. (4 dark fabric - 2 light fabric)

Then cut the squares diagonally twice to make 32 quarter square triangles.

After cutting the squares into HSTs & QSTs, pre-trim their points,
so it will be much easier to line them up and sew them together.

Using a point trimmer like the Prep-Tool ensures accurate pre-trimming:

HSTs: Use Short Side Trim

Line the Prep-Tool along the short sides of the half square triangles.

QSTs: Use Long Side Trim

Line the Prep-Tool along the long sides of the quarter square triangles

The video below shows how to trim points, using the Prep-Tool:

How to sew the triangles together for the 9 & 16 patch blocks

There are 3 combinations of triangle squares:

Made of 2
half square triangles

Made of 1 half square triangle and 2 quarter square triangles

Made of 4
quarter square triangles


Includes 3-Part Triangle Squares

Includes 2-Part and 4-Part Triangle Squares


2-Part Triangle Squares:

Line 2 HSTs up
right sides together.


Sew together with a
scant 1/4" seam allowance.


Press them open with
the seam to the dark,
purple side.

3-Part Triangle Squares:

Line 2 QSTs up right
sides together & sew.


Line the 2 sewn QSTs up with an HST & sew.


Press them open with
the seam to the dark side.

4-Part Triangle Squares:

Line 2 sets of 2 QSTs up
right sides together & sew.


Line 2 sets of 2 sewn
QSTs up together & sew.


Press them open.

To make sure the points on your triangles stay pointy in your finished block,
you want to sew them together with a scant - slightly less than - ¼” seam allowance.
Click on the next heading below to see how.

Click the headings below to open. - Click again to close.

How to use the Prep-Tool to align the Seam Guide at a Scant ¼” on your sewing machine.

Butt the Prep-Tool up against the needle of your sewing machine on the side with the gold lip edges. Peel the paper off the Seam Guide and butt it up against the other side of the Prep-Tool and stick it down in front of your presser foot.

Remove the Prep-Tool and guide your fabric against the Seam Guide for accurate Scant 1/4" seam allowances.

Every Finished-Size Quilting Set comes with a Prep-Tool, 8-Page booklet and 6-Pack Seam Guides.

See how to set the seam guide to sew Scant 1/4" Seams:


Making Square in a Square Blocks is Just as Easy: