Question 1: First a No-Brainer --- If the Finished-Size of this 16-patch block is 12", what is the Finished-Size of each patch?

a: 3 ¼"

b: 3 ½"

c: 3"

d: 4"

The Answer is c: 3"!

In our Quilt Quiz #2, we showed how the Finished Size of a Block divided by the number of patches in a row equals the Finished Patch Size. This is a 16-patch block and there are 4 patches in row, so 12" ÷ 4 = 3".

Question 2: Next a Half-Brainer --- If the Finished-Size of the same block is 9", now what is the Finished-Size of each patch?

a. 2 ½"

b. 2 ¼"

c. 2 5/8"

d. I don't do fractions!

The Answer is b: 2 ¼"!

This one is a little trickier because the answer doesn't come out a whole number. If you use a calculator:

9" ÷ 4 = 2.25"

Then you have to know that .25" is ¼" or Use This Chart:

If you answered d. I don't do fractions!, maybe this will change your mind.

To get the finished patch size of any 16-patch block, it makes it simpler if you use the Half and Half Method by dividing the finished block size in half, and then divide it in half again.

So what can you do with this?

How about making 9- and 16-patch blocks the same size like this:

Question 3: Now this one is a Full-Brainer --- If the Finished-Size of the same block is 10 ½", now what is the Finished-Size of each patch?

a. 2 ½"

b. 2 ¼"

c. 2 5/8"

d. Refer to d. above!

The Answer is c: 2 5/8"!

Now you'd have to be impressed if someone could do this one in their head. But if you use a calculator, you'll see:

10.5" ÷ 4 = 2.625"

Then you have to know that .625" = 5/8" or Use This Chart:

You could also use the Half and Half Method to simplify the process:

How about custom sizing a block to fit anywhere you want?

You can make a block fit exactly the way you want on a jacket, a purse or a pillow case. Simply measure the space you want it to fit into and divided by the number of patches in a row.

The answer may not come out to an exact 1/8" but you can use our chart to round up or down to the nearest 1/8" and get very close to the exact size you want.

Question 4: Now that our brains are fully warmed up, let's throw in some rectangles. If the Finished-Size of this Churn Dash block is 6", what is the Finished-Size of the rectangles?

a. 1" x 2"

b. 1 ¼" x 2 ¼"

ac 1 ½" x 2 ½"

d. Okay, now your just making me dizzy!

The answer is a: 1"x2"!

You already know how to get the Finished Patch Size:

6" ÷ 3 = 2" (Finished Patch Size)

Two rectangles need to fit in the 2" Patch, so each rectangle needs to be 1"x2".

Question 5: If the Finished-Size of the same Churn Dash block is 9", now what is the Finished-Size of the rectangles?

a. 2" x 4"

b. 1 ½" x 3"

c. 2" x 3 ½"

d. Have you guys ever heard of following a pattern!

The Answer is a: 1½" x 3 " !

The Finished Patch Size is 3" (9" ÷ 3 = 3"), and two rectangles need to fit in the 3" Patch, so each rectangle needs to be 1½" x 3".

So, what can I do with this?

How about resizing your favorite patterns?

If you answered d. Have you guys ever heard of following a pattern! We just want you to know that we love pattern designers. Many of our best friends are pattern designers. It's amazing how they can visualize how to combine the different colors and values of fabrics into a work of art.

But have you ever tried to resize a pattern that you love? It's just a math nightmare trying to keep track of all the different seam allowance measurements.

But, have you noticed how patterns
almost always tell you the Finished Block Size?

Use the formula below to find the Finished Patch Size:

The thing is, if you want to change the size of a pattern, the only thing you want to change are the finished sizes. The seam allowance never changes whether you are making a 2" HST or a 10" HST you still need to add 0.854" to include an exact 1/4" seam allowance all around the pieces.

So the conventional way to change the sizes in a pattern is to subtract the seam allowance out of the measurements given, then adjust the finished sizes up or down and then add the seam allowance measurements back in...Whew!

Or, you could use our Seam Allowance Additions and just adjust the Finished Sizes to the size you want.

It's this simple, the Seam Allowance measurements that never change are on the edge of the ruler. So now the measurements you line up to on the ruler are the Finished Sizes, that you want to change.

And the Seam Allowance? It's added right on the edge of your ruler, never changing, just like it's supposed to.

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The purple S, green H and red Q Addition adds the exact seam allowance amount
for Squares, Half Square Triangles and Quarter Square Triangles.

As shown in the animation above, if the pattern is for a 9-Patch block and its finished size is 6", the Finished Patch Size is 2". Change the Finished Patch Size to 3" and you'll make a 9" Finished Block. Increase it to 4" and now you'll make a 12" Finished Block.

Now you can figure out the Finished Patch Size of
more complex blocks like these.