How Many 12 Inch Blocks Do I Need to Make a Quilt?
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The 12 inch finished quilt block is one of the most popular in quilting. Whether the design is simple or complex, the size is great because you can quickly piece together a decent-sized quilt.
Because of the popularity of the block size, you may find yourself with several leftover blocks hanging around. Or perhaps you’ve found a block pattern that you LOVE and you want to make an entire quilt out of the design.
HELPFUL TIP: A 12″ finished block means that it is 12″ after it is sewn into the quilt top. A single block would be 12 1/2″ due to the 1/4″ seam allowance on every side. In this post, I am referring to a 12″ finished, 12 1/2″ unfinished quilt block size.
Let’s put those blocks to good use and discover how many 12″ blocks you need in order to make a quilt. But how do you determine how many 12″ blocks you’ll need for your project? Let’s find out.
Before you can determine how many 12″ blocks you need for a project, you’ll need to decide on what size quilt you want to make. If the quilt you’re making is meant for a bed, you can use the mattress size. Remember to add several inches if you want the quilt to hang off of the bed.
Check out my free printable quilt size chart if you need a refresher on quilt sizes!
If your quilt is not meant for a bed, you can be more flexible with your measurements and use some of the suggested sizes in the examples below.
After you know your desired quilt size, you can calculate how many 12″ blocks you need for your quilt, or you can use my example calculations below to get a general idea of how many you’ll need.
My calculations do not account for sashing or borders. If you want to add sashing or add borders, you’ll need to adjust these calculations.
Please use my calculations for reference only, and be sure to double-check your quilt math!
Want to save this information for later? Download this FREE 12″ Blocks in a Quilt cheat sheet! This cheat sheet shows how many 12″ finished blocks are needed for 11 sizes of quilts.
How Many 12 Inch Blocks Does It Take to Make a Baby Quilt?
In order to make a 36″ x 48″ baby quilt you will need 12 12″ finished blocks arranged in a 3 x 4 grid.
This is a great use of extra blocks you have! Sew a few orphan blocks together and you’ll have a quick and easy baby quilt.
Want the quilt a little bigger? Try adding sashing and borders.
How Many 12 Inch Blocks Does It Take to Make a Throw Size Quilt?
To make a 48″ x 60″ small throw size quilt you will need 20 12″ finished blocks arranged in a 4 x 5 grid.
If you’d like to make a bigger throw quilt, try using 30 12″ finished blocks arranged in a 5 x 6 grid. This will give you a generous 60″ x 72″ throw quilt.
How Many 12 Inch Blocks Does It Take to Make a Twin Size Quilt?
To make a 72″ x 84″ twin size quilt, you will need 42 12″ finished blocks arranged in a 6 x 7 grid.
How Many 12 Inch Blocks Does It Take to Make a Full Size Quilt?
To make a 84″ x 108″ full size quilt, you will need 63 12″ finished blocks arranged in a 7 x 9 grid.
How Many 12 Inch Blocks Does It Take to Make a Queen Size Quilt?
To make a 96″ x 108″ queen size quilt, you will need 72 12″ finished blocks arranged in an 8 x 9 grid.
How Many 12 Inch Blocks Does It Take to Make a King Size Quilt?
To make a 108″ x 108″ king size quilt you will need 81 12″ finished blocks arranged in a 9 x 9 grid.
How to Calculate How Many 12 Inch Blocks Are Needed For a Quilt
Sometimes the suggested quilt sizes just won’t do and you want to make a custom size quilt! In that case, a bit of math is required to figure out exactly how many blocks you’ll need for your project. Learn how to do the quilt math below!
Let’s do a quick example:
We want to make a baby quilt. According to these quilt size guidelines, a good baby size quilt is 30″ x 40″. We’ll base our measurements on that guideline.
To determine the number of 12″ finished blocks needed, divide 30” / 12” to get 2.5. Because we don’t want a partial block, round that up to 3. We will need 3 blocks to reach the desired quilt width of 30”. The width will technically be 36″ (3 x 12 = 36).
Now let’s do the length. Divide 40” x 12” to get 3.33. Again, we’ll round up to the nearest whole number: 4. We will need 4 blocks to reach the desired quilt length of 40″. The length will be 48″ (4 x 12 = 48).
To get the total number of blocks needed, multiply the number of blocks together. 3 x 4 = 12 blocks. We need twelve 12″ finished blocks to make a 36″ x 48″ baby size quilt.
Apply the same math to any quilt size to make your own custom quilt!
HELPFUL TIP: When calculating how many 12″ blocks you need for a quilt, be sure to account for any sashing or borders you may want to add. Adding sashing and borders will lower the number of blocks you need in your quilt.
For example, if you want a 4-inch border around your quilt, subtract your desired quilt size by 8” to account for your borders BEFORE you calculate how many blocks you will need.
12 Inch Block Quilt Size Chart
Below is a chart that shows suggested sizes for quilts using 12″ finished blocks.
| Quilt Size | Inches | Number of Blocks | Block Layout |
| Pillow | 12″ x 12″ | 1 | 1 x 1 |
| Wall Hanging | 24″ x 24″ | 4 | 2 x 2 |
| Baby | 36″ x 48″ | 12 | 3 x 4 |
| Lap | 48″ x 48″ | 16 | 4 x 4 |
| Small Throw | 48″ x 60″ | 20 | 4 x 5 |
| Large Throw | 60″ x 72″ | 30 | 5 x 6 |
| Twin | 72″ x 84″ | 42 | 6 x 7 |
| Full/Double | 84″ x 108″ | 63 | 7 x 9 |
| Queen | 96″ x 108″ | 72 | 8 x 9 |
| King | 108″ x 108″ | 81 | 9 x 9 |
| California King | 108″ x 120″ | 90 | 9 x 10 |
Now you know how to figure out exactly how many 12″ blocks you’ll need to make a quilt! Remember to download the free cheat sheet so you can save this information for later!
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