Making a Quilt: Design and Math

Quilting is a semi-unusual hobby for people my age and I often have people tell me “I could never do that! It looks so hard!” Its SERIOUSLY not hard. You have to know how to sew a straight line, you have to use a little math (or just find a pattern), and you have to have the time and desire to actually sit down and make the quilt. That is it. As I work on this quilt I’ll update my tutorial with each phase as I get it done.

Let’s get started!

The very first thing you need to do is DESIGN your quilt. Quilts come in a million and one different patterns ranging from extremely easy to extremely complicated. I usually go for easier patterns because I quilt for fun and I don’t want to worry about matching up 8 cornered stars. You can definitely go to the fabric store and find patterns for quilts that will give you step-by-step instructions, or find instructions online. No shame there!

I just prefer to draw my own. The math is soothing. At this point I have a mental database of quilt patterns I’ve done before so I can just decide what I want to do and draw it, but for a beginner, try googling “beginner quilt patterns” and see what you find. Once you find a picture of one that you like, draw a diagram of it so you can start figuring out how much fabric you’ll need. Here is my diagram that I had drawn for this quilt:

As you can see, my quilt is composed of 5 rows and 3 columns of “primary” blocks. And each primary block is comprised of 4 “secondary” blocks. A lot (or most) quilts use the same kind of primary block over and over through the whole quilt, but I decided to alternate two similar but different primary blocks to create a pattern. I’ve never made a quilt like this before so I hope it turns out well!

As you can see above, I labeled my primary blocks as Block A (for the 3 fabric blocks) and Block B (for the 2 fabric blocks). This is going to help me keep everything straight. I also color code my quilts so that when I’m figuring out how much fabric to buy I can assign each one a “color” and not get confused about what is for what (super important when you buy fabric for a project then don’t do the project for several years).

To figure out how much fabric to buy, you need to first figure out how big you want the quilt. I decided this would be a “cuddle quilt,” or a throw. I usually do this size because they get used a lot more than if I were to make bed quilts (that would have to match a decor, etc).

I decided on 45×75 inches, and got to work. That size quilt means each primary square has to be 15″ square (finished). Each primary square is comprised of four secondary squares that are each 7.5″ square.

Block A uses 3 fabrics, and thus the (finished) size of each fabric strip will be 7.5″ x 2.5″ (divide 7.5 by 3). In my drawing, these strips are colored yellow, green, and brown.

Block B uses 2 fabrics, and thus the (finished) size of each fabric strip will be 7.5″ x 3.75″ (divide 7.5 by 2). In my drawing, these strips are colored white and blue.

The most important thing to remember when you’re figuring out the sizes is SEAM ALLOWANCES! You are going to be sewing all four sides of every piece of fabric, so the finished size will be smaller than the size you cut out. I always use 1/4 inch seams so I add 1/2 inch to all dimensions (to compensate for seam allowances on both sides).

Thus, yellow, brown, and green fabrics (from drawing) will be 8″ by 3″; and white and blue fabrics will be 8″ by 4.25″.

Now you know how big your quilt is going to be, and how big each piece of fabric needs to be, so all you need to do is figure out how many of each type of quilt piece you need!

For those pieces in Block A (green, yellow, brown), there are 8 primary blocks. Each primary block has 4 secondary blocks, and each secondary block has 1 of each color. 8 x 4 x 1 = 32 pieces of green, yellow, and brown. Fabric varies in width but its usually between 42 and 45 inches wide.

You can get five 8 inch cuts out of one width of fabric, and you need 32 total. Always round up in quilting, so 32/5 = seven 3 inch widths are needed. 7×3 = 21 inches, so buying 3/4 yard of fabric will leave plenty.

For the Block B pieces (white and blue), there are 7 primary blocks. Each primary block has 4 secondary blocks and each secondary block has 1 of each fabric. 7 x 4 x 1 = 28 pieces of each fabric.

Once again you can get five 8 inch cuts out of one width of fabric, and you need 28 total. 28/5 = six 4.25″ widths needed. 6 x 4.25″ = 25.5″, which means 1 yard is plenty.

To sum up:

3/4 yard of green, yellow, and brown
1 yard of blue and white

Have I TOTALLY lost you? I promise its not as hard as it might seem. Think it through, and feel free to ask me questions if I didn’t explain something well.

Or, just download a pattern from online so someone else does all the calculating for you!

Next up: picking your fabric, and cutting strips!


5 thoughts on “Making a Quilt: Design and Math

  1. “The math is soothing”? SOOTHING? There is something wrong with you, my friend! πŸ™‚

    Yes, you totally lost me with all the calculations, so therefore, if I ever decide to make a quilt, I’ll either have to use your exact pattern or find one online, like you said. However, I don’t see myself quilting any time soon, so I’ll just live vicariously through you, mmmkay? Mmmkay.

  2. haha i have no problem with that! And yes, it is soothing! It’s like a puzzle. Use math to figure out exactly how much fabric of each type you need to make a quilt… I love puzzles πŸ™‚ If you ever DO want to try a quilt let me know and I’ll draw your pattern for you. Maybe one for baby b? πŸ™‚

  3. Oooh…I might have to take you up on that. Of course, first, I’d have to buy a sewing machine, learn how to sew a straight line, and find the hours in the day to do it…but sure! Once all those things happen, I’ll hit you up for a custom Lyndsey design….do you have one that I could *do in 15 minutes*… πŸ™‚

  4. If I sent you a photo of the quilt and the measurements of fabric that it requires could you tell me how big I would need to cut the strips and blocks?

  5. @Christine- Like I said… i am a total nerd and actually enjoy doing this stuff so I’d be happy to help! If it is a complicated design I may not be able to because I’m not a very advanced quilter, but I will definitely take a look and let you know if I can help you. You can email me at

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