Changing the Dimensions of a Jelly Roll Race Quilt
In my last blog,“Ready, Set, Sew! A Jelly Roll Race Colorado Springs”, I explained how to create a Jelly Roll Race quilt from a 40-strip jelly roll. Using the standard 40-strip jelly roll, you will get a quilt that is 50″ x 64″ without any additional border. If, however, you want to create a larger quilt, you need to know how to change the dimensions of a Jelly Roll Race quilt.
How to Create a Bigger Jelly Roll Race Quilt
If you want a bigger quilt, using jelly roll strips, it’s easy to do. As my son would say, we need to” put some math on it” to calculate how many more strips you need. The calculations are a little different for the length versus the width of the quilt.
Changing the width
The width of the Jelly Roll Race Quilt is determined by the length of your initial mega strip. Assuming you would like a horizontally striped quilt, you can change the width by adding or subtracting the number of strips used initially.
From my earlier blog, you know that the fabric strips in a jelly roll are around 42 inches wide. There is some loss due to the selvage edge and the 1/4″ seam allowance on each side. So it makes the math easy to round the width to approximately 40″. Thus, 40 strips x 40″ = a 1600″ mega strip.
After each fold of the strip, when you sew the seam down the long side, you lose half the width. So after 5 folds, your quilt is 50″ wide : 1600″ to 800″ to 400″ to 200″ to 100″ to 50″.
Now, let’s say you want an 80″-wide queen sized Jelly Roll Race quilt. (no border). Let’s work backward. Double 80 five times: 160″, 320″, 640″, 1280″, 2560″. So, you need an initial mega strip that is 2560″ long. That will be sixty four jelly roll strips (2560÷40). Those first couple rows will sure take a while to sew!
Read on to find out how to change the length.
Changing the length
You must change the length by a different method. Five folds to get the width will always result in a 64″ long quilt (2″ per row; 32 rows per mega strip). Thus with 2560″ initial strip, once sewn, you’d have a Jelly Roll Race Quilt 80″ wide by about 64″ long. If you want the strips to run horizontally, and don’t want a border, you need to add length. For a queen sized quilt you probably want it to be about 96″ long.
In order to add length, you must make a separate piece. Why? Well, you have probably noticed the length pattern by now. Every time you fold your strip you double the number of rows of your Jelly Roll Race Quilt top. We can assume each row is 2″ tall since the initial jelly roll strips are 2.5″ inches tall with a 1/4 seam allowance on each side. If you fold the piece a sixth time, you’d end up with 64 rows –128″ in length. That’s too big — and it would narrow the quilt to 40″!
The first 64 strips gave you a quilt that was 80″ wide and 64″ long. So you need and additional 32″ to add to the bottom, so your quilt will be 96″ long (and still 80″ wide). The solution is to add another section to the bottom of the original Jelly Roll Race Quilt top. Adding 16 rows will give you an additional 32″ of length. So 64″ + 32″ gives us a reasonable queen sized quilt top of 96″ long.
To get a 32″ long piece you would need 16 rows that are 80 inches wide. This is four folds of a mega strip. One strip folded upon itself to make two, then four, then eight, then sixteen. Therefore you need a strip 1280″. (16 x 80″). For that strip, you will need 32 jelly roll strips (1280″ ÷ 40 strips = 32 jelly roll strips.) Follow the same Jelly Roll Race Quilt directions, as described in “Ready, Set, Sew! A Jelly Roll Race Colorado Springs”, for this add on section. After you complete this section, just add it to your original piece by sewing the second piece to the bottom of the first piece.
Your queen sized Jelly Roll Race Quilt, with horizontal strips, and no border, will take 64 strips for the initial quilt + 32 strips for the add-on section = 96 strips need for the whole Jelly Roll Race Quilt top. So you need 3 fabric jelly rolls (with 40 fabric strips in each jelly roll) to make this quilt.
Here’s the Math Part
A formula to just figure out how many strips you need for your Jelly Roll Race Quilt is:
So, for our 80″ wide, 96″ long quilt, we multiply 80″ width by 48 rows (each row is 2″, giving us 96″ in length) = 3840. Now divide 3840 by the strip length which is approximately 40″ once sewn. Therefore, you need 3840/40 = 96 strips.
You can now easily figure out how many strips you will need for any size Jelly Roll Race Quilt. Just remember, the length will be determined by the number of rows and that is a set number. Only the width is completely flexible. To add to your length you will have to make two separate pieces and combine them.
You can always vary the number of rows for each “section”. It’s just easy to count on 64 rows from one 40-strip jelly roll.
Here are the standard mattress sizes. Of course you will want your quilt to hang down a bit all around. But this will help you with your calculations.
Twin: 39 in × 75 in
Double/Full: 54 in × 75 in
Queen: 60 in × 80 in
King: 76 in × 80 in
For a crib quilt, for course, you’ll use less strips than the 40 that comes with a full sized jelly roll. A 20 strip jelly roll would start out as an 800″ mega strip (20 strips each 40″ long). So 4 folds of that would give you a little quilt that is that’s 16″ rows or 32″ long and 50″ wide 800″ first fold to 400″; second fold to 200; third fold to 100″ fourth and last fold to 50″. You could always cut your initial strips is half to give more variation on a little quilt. You will just need double the initial strips if they are half the length.
Here’ a pdf file from Liz Katsuro that provides some great guidance on changing the size of your Jelly Roll Race quilt . She even includes a chart for 30 different custom sizes, and how many strips are needed for each.
Other Ideas for Jelly Roll Race Quilts
If you look around on the web for Jelly Roll Race Quilts, you will see many a lot of images of different quilts that people have made. I’ve captured a few of them for you to see how you can modify your Jelly Roll Race Quilt with applique or by adding some blocks in between the strips. Just let your imagination run wild!
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