Jelly Roll Race Quilt :: Changing the Quilt Size & Determining Number of Strips

Jelly Roll Race Quilt :: Changing the Quilt Size & Determining Number of Strips


Welcome to the third part of our Jelly Roll Race Quilt series. Be sure to read part 1, Jelly Roll Race Quilt :: Make a Quilt in an Hour?!  and part 2, Jelly Roll Race Quilt :: Directions & Notes.

So your standard Jelly Roll Race Quilt makes a finished top that is approximately 50 x 60 inches. This is fine for a throw quilt, or if you add a border it would work for a full sized bed. But if you want to make a Jelly Roll Race Quilt for a twin, queen, or king sized bed, you need to do some math.

First of all, in order to change the size of the Jelly Roll Race Quilt, you have to understand how the quilt comes together. The width of the Jelly Roll Race Quilt is completely determined by the length of your initial mega strip. Assuming you would like a horizontally striped quilt, we can easily change the width by adding or subtracting the number of strips we add to our first mega strip. It is the length that gets a bit tricky.

Usually the fabric strips in a jelly roll are around 42 inches wide. We will assume some loss due to the selvedge edge and account for a 1/4″ seam allowance on each side, so we will round each strip width to approximately 40″. So 40 strips x 40″ = a 1600″ mega strip.

Now each time you fold the strip in half and sew up the side seam you loose half the width. So your width looks something like this…


mega strip 1600″ wide
double row 800″ wide
four layer row 400″ wide
eight layer row 200″ wide
sixteen layer row 100″ wide
thirty-two layer row 50″ wide

To figure out your quilt size you can work backwards from that. Let’s say you want an 80″ wide queen sized Jelly Roll Race Quilt and figure 80 (double it 5x), 160, 320, 640, 1280, 2560… so you need an initial mega strip that is 2560″ long. Take your total mega strip length and divide it by the 40″ jelly roll strip length and that will give you how many strips you need to sew together. 2560″ mega strip / 40″ jelly roll strip = 64 jelly roll strips needed.

Now, you may have noticed that we haven’t changed the length at all. Using those 64 strips, your Jelly Roll Race Quilt will work out to be 80″ wide by about 64″ long. Now you could turn this Jelly Roll Race Quilt top sideways, so the strips run vertically and add a border (which is what I did with my “I Want Crazy” quilt) but if you want it to run horizontally and not a have a border we need to add length. For a queen sized quilt you probably want it to be more like 90-100″ long.

In order to add this length, we actually have to 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.

1 row = 2″ tall
2 rows = 4″ tall
4 rows = 8″ tall
8 rows = 16″ tall
16 rows = 32″ tall
32 rows = 64″ tall

Here is the problem… if we just fold it again and do another row like all the other rows we end up with Jelly Roll Race Quilt top that is 64 rows tall, approximately 128″ tall, which is of course, way too big and would take a ton of fabric.

The solution is to add another section to the bottom of our original Jelly Roll Race Quilt top. Looking at the chart above, we can see that adding 16 rows will give us an additional 32″ of length. So 64″ + 32″ gives us a reasonable queen sized quilt top of 96″ long.

For this extra section we need to double our 80″ width 4 times, not 5 like the original top piece… 80, 160, 320, 640, 1280. So we now need a second mega strip that is 1280″ long / 40 strips = 32 jelly roll strips. Follow the same Jelly Roll Race Quilt directions for this add on section. After you complete this section, just add it to your original 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.

A quicker formula to just figure out how many strips you need for your Jelly Roll Race Quilt is this…

(inches wide x number of rows) / 40″ strip = number of strips needed

Lets try it… 80″ wide x 48 rows = 3840 take that and divide by strip length 3840/40 = 96 strips… TADA!

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.

Here are the standard measurement for 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 Γ— 75 in
Double/Full: 54 in Γ— 75 in
Queen: 60 in Γ— 80 in
King: 76 in Γ— 80 in

Also, you can scale it down to make a super fast baby quilt with vertical strips. 42″ x 32″ (I like to keep my baby quilts sized to fit using 1 yard of fabric for the backing). So this would be 42″ wide x 16 rows = 672. 672/40″ = 17 strips. 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.

I hope that helps you figure out how to size your Jelly Roll Race Quilt to fit any size bed. Good luck and having fun sewing!


Michelle ~ Wee Folk Art


  1. Hi Michelle,  I appreciate your posts on the jelly roll race pattern.  I plan to make a baby quilt using your size guide.  Do I still need to cut off a portion of the original long strip before sewing the sides together?  In the original pattern, using 40 strips, 18″ are cut.  Any idea how much would need to be cut if I used 17 strips?  Many thanks!



    1. You will still need to cut off about half of the first strip (it can be a bit less than half). This is to offset where the strip seams meet once you start sewing the rows together. I haven’t made one this size yet so I don’t know how much that will effect the overall size of the blanket. You might want to use 18 strips just to be sure you get enough length. Hope that helps.

      1. I’ll let you know how it turns out (assuming I get around to making it!).

  2. Your information about changing the size of the quilt is awesome. However, how would I do the measuring if I were to cut my own strips wider than the conventional jelly roll 2 1/2 inches? Say, for instance, a six inch strip by width of fabric? I have tried to do this myself but my math is failing me. 

    1. Ok… so let’s try this…

      6″ wide strips would leave you with 5.5″ of finished width. So 5.5 x 16 rows = 88 inches long… which if you rotate it, is a good width for a queen sized quilt. This means you are only going to do 4 seams along your mega-strip (not 5). So now, let’s say you wanted it to be 100″ long (that gives you an 88×100 inch quilt with a vertical alignment)…

      (inches wide x number of rows) / 40″ strip = number of strips needed

      ( 100 x 16 ) / 40 = 40 strips


      If you want it to have a horizontal alignment you will have to do the Add-On portion at the bottom. So

      ( 88 x 16 ) / 40 = 35.2 rounded up to 36 strips plus you have to add-on a bit of length… 2 more rows should give you 99″ long

      ( 88 x 2 ) / 40 = 4.4 rounded up to 5…. 36+5 = 41 strips


      The other option would be to do a horizontal alignment but add a border. So let’s try 68 wide by 88 long

      ( 68 x 16 ) / 40 = 27.2 rounded up to 28 strips… then add a 5-7 inch border around the outside to get a finished quilt with stripes that run horizontally.



      1. This is SO why I was an English major.  But, maybe I would have learned math if they had applied the principles to quilting…..

        1. LOL – I always feel like I use the most math ever in my life while standing in the middle of Joann’s or Home Depot. I often say that Joann’s makes my brain tired. Unfortunately home ec, shop class, and all those other “fluff” classes seem to have been lost to make way for more college prep classes. It is a real shame because those life skill classes are where you can really make math meaningful for many students. Increasing patterns, calculating yardage needed, doubling a recipe, figuring out flooring square feet, measuring to cut crown moldings (that’s a tricky bugger), estimating the cost of tiles, etc… all give a true hands on application for all that math.

          If you are interested in another Math in Crafting post check out my tutorial on how to reduce or enlarge patterns.


          Anyway, I’m glad the post helped. πŸ™‚


          1. I totally agree. I use “real life” math every time I quilt, sew, create a pattern, bake, cook or do home repair stuff.

  3. Thank you so very much for taking the time to put all of this in print. It was so easy to understand. I just attempted my first jelly roll quilt top using your directions for the queen size. It worked perfectly! Thank you! Do you also have instructions to determine how much fabric to buy for the backing and binding?!

  4. Hi!  I’m going to give this a try.  Yours is so beautiful!  

    Do you have to press the seams in between sewing together or all at the end?  Thanks so much!


    1. No – you do not press the seams as you go. That would definitely take longer. I just did it all at the end.

  5. Nice to find another Maths nerd amongst quilters – I would have done that as well

    1. How many strips to I need to make a full size quilt? I have 6 patterns and cutting them 2 inches wide by 22 long

  6. I was wondering how to finish up the Jelly Roll quilt i made this morning, I will be putting a border on it. and a basting polester/cotton,,,Do I have to do the ditch stitch through out the quilt ? or do you have any suggestions. How is everyone else doing the backside of their Jelly Roll quilt (finishing it up) ?

    Thank you so much for helping me (beginner sewer ) out.    thank you!  Gail Briney

  7. I want to make a twin size quilt with the Jelly roll race.  Can you tell me what the easiest way would be to make this?

    I am thinking to just make the jelly roll race normally but add borders. But I would only want to make it longer not wider. Any suggestions?



    1. If you can make a Queen size quilt from 1 Jelly roll and adding boarders, can you make 2 twin size quilts with one Jelly Roll? If not how many strips would it take to make 2 twin size quilts with boarders?

  8. Hi. Thanks for this page.  I make these quilts for a hospice. I need to change size 54 x100 inches  finished. Strips cut 3 1/2 inch wide. My question is how many strips to cut. Thank you kim 

  9. hello, I want to Mae a baby quilt for toddler bed but for strips to be horizontal not verticAl… Help!

    1. What would you like the final size to be? You may have to make it in two sections and join them.

      For a 32″ square it would be one section… 32×16/40=12.8. So round up to 13 strips.

      For a 32×40″ rectangle it would require two sections. First make the square above… and then you will have to add another 8 row section. 32×8/40=6.4. So round up to 8 and then add in the original 13 strips. You will need 20 strips all together.

      1. Ahhhhh yes….. Toddler mattress/ bed size is 27x 52. I was thinking 40x 60.

        1. Well you will have to make it just a bit longer to work out right. Look at the row height chart listed in the post. 32 rows = 64″.

          40×64 is easy to do. 40×32/40… so 32 strips.


    hello and many thanks for your instructions. 

    After reading through I don’t seem to see anything referring to the ‘pick up’ order of the strips. 

    Yes I realise I can do random but on one video I saw it just picked them up in the order they unrolled. Wanting to make it bigger that would double the same fabric each time. Being new to quilting I can’t actually visualise how that will look. 

    Apologies for this silly question but I don’t want to waste the rolls. 

    Many thanks. 


    1. Michelle

      There is no real way to control how the strips line up in stacked form. Some rolls have multiple strips of the same fabric right after each other, some have them more spread out. I choose to open up my rolls and pull strips in a more random order so I didn’t have two of the same color sewn directly to each other in a line… but of course some of them did end up stacked. In my first post I did mention that I didn’t like the pooling that occurring in one section so I did seam rip and then flip over one of the sections to spread out some of the green. But the same fabric touching in places is inevitable. The surprise of how it will turn out is part of the fun. Enjoy!

  11. I want to make a King Size Jelly Roll Quilt, Long on sides because I don’t use a bed skirt. How many 40 – 2 1/2″ strip jelly rolls will I need for each quilt and I’m not exact ally understanding how I add the extra 32 to add my extra length. Could you please explain for King instead of Queen. I made the mistake of my first attempt at a quilt ever being a jelly roll King . Thank you, your explanation has been the most helpful.

    1. Michelle ~ Wee Folk Art

      King Mattress: 76in x 80in

      You can easily make it 96in long (by adding 16 more rows) to over hand bottom of the bed 16in. So I will calculate with 16in over hang on either side which gives us a quilt 108in x 96in (without a border).

      All together it will be 48 rows long with the strips running horizontally across the bed.

      (inches wide x number of rows) / 40 strip = number of strips needed

      108in x 48 / 40in strip = 131 strips (rounded up a bit)
      which means you will need 3 u00BC jelly rolls that include 40 strips

      To make this quilt you will have to make two separate sections that you sew together.

      Section one: 108in x 32 rows / 40 = 87 strips

      Section two: 108in x 16 rows / 40 = 44 strips

      Sew the two sections together to make the quilt top.

      Hope that helps.

    1. Michelle ~ Wee Folk Art

      When you leave a comment you can click on the box “Notify me of follow-up comments by email” just below the post comment button. It will email you any updates.

  12. Excellent instructions…which I will use for future jelly roll quilts. However, I’m in need of advice. I messed up sewing one row too many and trimmed the bottom. Eeeek! It’s way too long and too narrow. How can I fix this. If I were to sew it back up…I’d have a seam running straight up the middle of the quilt. I’m open for any suggestions. Thank you for your time.

    1. Michelle ~ Wee Folk Art

      Oh no. Sorry, I don’t really have any other suggestions to fix it. Sewing it back up the middle is the only thing I can think of since it was already trimmed.

      Maybe someone else here can post an idea?

      1. Perhaps the top could be cut into 3 equal pieces from top to bottom and sashing added between the rows. A border that matches the sashing could help get the total width just right.

        1. Kimara

          Great idea! Hope Sam stops back to read your advice. Thanks for sharing. ~Kimara~

  13. Please check my math. I want to make a wall hanging around 30×32. If I cut 5 inches off a strip (so I can have 2 1/2″ charms for other projects), it’ll make the strips 35″ long,
    (30 x 16)/35 = 13.71 or 14 strips.

    If I want more variation, I can cut those 14 strips in half, right? (I bought a roll of 20, so I’m thinking of cutting all 20 and using 28 of them (20 plus repeating 8 favorites.)

    Thanks for this tutorial. I love the idea of the jelly roll race, but I don’t really want large quilts. I prefer to do wall hangings.

    1. Michelle ~ Wee Folk Art

      I see that I’m a little late in replying. I hope your quilt worked out well. If you are still wondering though here are a couple thoughts to keep in mind.

      You are going to lose a bit of length due to seam allowance… so for safety sake I would base it on strips 34″ long. This also gives you a little extra for the piece you need to cut off at the beginning.

      (30×16) / 34 strip = number of strips needed… which is a little over 14 so round up to 15

      I would use 15 strips and then trim the finished size. You can cut them in half… but again make sure you have enough to cover the seams. 35/2 = 17.5 – if you use 1/4″ seams than you can base your calculations on 17″ strips, also remember you need a bit of extra to cut off at the beginning.

      (30×16) / 17″ strip = round up to 29 (I might use 30 just to be sure).

      With a small quilt like this, it is easy enough to trim the final top down to the extract size you want… so I would tend to err to a tiny bit big if I had enough fabric.

      1. Thanks for your advice. I actually haven’t started it yet, as I had a couple other things to do first. I’m looking forward to trying this. I think it’s just the project I need to begin with–my sewing/quilting is a bit rusty.

  14. I want to use batiks and not have the split in each row, just want eac row with the sone strip so if I do not cut the 18 inches off will I gave solid rows?

    1. Michelle ~ Wee Folk Art

      No, I don’t think it will still come out perfectly even unless you have fabric strips that are exactly as long as your finished quilt width.

      But in that case, I think it would be easier just to sew the strips on top of each other and not mess with the whole long, mega strip.

  15. Tell me if I’m wrong but it looks like your calculations . for a jelly roll race quilt for a queen size bed should work for a king size bed also. If not, how many do I need for a king size jelly roll race quilt? I’m horrible at math. Thank You.

    1. Michelle ~ Wee Folk Art

      Hi Timothy,
      If you scroll through the comments you will find a reply that I have already posted about making a king sized quilt. Check there first and then let me know if you have anymore questions. Enjoy!

      1. I found the post that you mentioned. Thanks that helps.

  16. I just bought some fat quarter fabric bundles. They measure 18 by 21 each. I would like to make a jelly roll quilt with them. Since a jelly roll has 40 strips that measure 2.5 by 42 each. With the fat quarter bundles that I got I figure that I would need 80 strips at 2.5 by 21 to make my quilt. Can you tell me if I’m right or not. Thank You.

    1. Michelle ~ Wee Folk Art

      I’m not sure how wide or long you would like your finished quilt but you just need to swap out the 40″ for 20″ in the formula.

      (inches wide x number of rows) / 20 strip = number of strips needed

      Based on the basic 50×60″ quilt… yes, you would need 80 strips.
      50″wide X 32 rows / 20″ strip

  17. Your instructions are awesome! I was getting ready to figure out the math problem and solution but googled first and found your post. You’ve already figured out the equation for me! Can’t thank you enough for sharing!
    Carla Sidwell
    Fort Worth, TX

  18. I’m going to be making a Twin 39 x 75 jelly roll race quilt for my Mom with 4.5 wide strips. I think I messed up the math. Inches wide x # of rows / 40 = # strips needed. Here’s what I got 39 x 32 / 40 = 31.2 or 32. Also would this be vertical or horizontal, because I want it to be horizontal. Thank You.

    1. Michelle ~ Wee Folk Art

      In your case, we can assume each row is 4 tall since the initial jelly roll strips are 4.5 inches tall with a 1/4 seam allowance on each side.

      1 row = 4 tall
      2 rows = 8 tall
      4 rows = 16 tall
      8 rows = 32 tall
      16 rows = 64 tall
      **32 rows = 128 tall** This is way too long!

      For a Twin 39 x 75 jelly roll race quilt that runs horizontally, you will need to make your quilt in two pieces. I would make the first one 16 rows and the second one 4 rows. When you join them together you should have an 80″ long quilt. So your quilt would be a total of 20 rows, once they are pieced together.

      I would also make it a big wider than the exact mattress top. Since your length will hang over the bottom by 5″ I would probably add 10″ to the width so it hangs down 5″ on either side. So lets think finished size of 50×80 inches.

      (inches wide x number of rows) / strip length = number of strips needed

      50″ wide X 20 rows altogether / strip length (I’m not sure how long your strips are. Are you using 20″ or 40″ strips?) = number of strips needed

      1000/20 = 50 strips OR 1000/40 = 25 strips NEEDED ALTOGETHER

      Just remember that you are making this quilt in two sections. The main piece that has 16 rows and a second pieces that is only 4 rows. So you will be making one mega long strip and setting aside the extra strips for a shorter mega strip.

      For the main part you will be working with 16 rows.
      (50″ x 16 rows) / 40″ long strips = 20 strips needed OR (50″ x 16 rows) / 20″ long strips = 40 strips

      Use the rest of the total strips for the second piece.

      1. The strips are 40 inches. Sorry I forgot to mention that. Also, thanks for the help.

  19. I have a red and white jelly roll, mostly red…I want to make it wider, which you just explained…but I want to work white in with it to make it larger….any tips on placement of white strips?

    1. Michelle ~ Wee Folk Art

      I don’t have any specific directions for random placement of the white strips. No matter what you do you may get some obvious pooling of the white. I’ve had some weird pooling of colors before and chose to seam rip one row when the top was done and flip a section over to eliminate some of the pooling. It added a bit more time but I was happier with the end result.

      in your case, I would probably alternate how often I added a white strip… sometimes after 2 reds, sometimes after 3 reds, and sometimes after 4 reds.

    2. You could add a 2 1/2″ square between each strip. That would make it a little bigger and give it some pops of color throughout.

  20. I have enjoyed making these jelly roll quilts. Someone mentioned that you can add a 2.5 square between each strip. Will I have to eliminate a couple strips to make up for the squares??
    I thought it will turn out neat with those squares the same as the border I put on.

    1. Michelle ~ Wee Folk Art

      Yes, the squares will add more length and therefore you will need fewer strips. Add up how many squares you plan to use. Multiply that by 2 inches (to account for seam 1/4″ allowance) and divide that total number by 40. Round that number down to determine how many strips to eliminate from the jelly roll.

  21. I love jelly rolls quilts. this would be my first one. anyway have a question regarding horizontal to vertical stripes ? would one make the bed look either smaller or bigger?? I have a craftmatic bed, which is two twin extra long”s to make a king still trying to figure if it is a eastern or northern. trying to figure out with what I read is confusing. how many rolls do I need, help if possible !

  22. Michelle, I’m having a hard time understanding the formula. If I wanted the quilt to be 90″ x 96″, are you saying 72 strips for Section 1 and 16 strips for Section 2? I’m sorry that this isn’t getting through to me. Thank you.

    1. Michelle ~ Wee Folk Art

      90 wide x 48 rows = 4320 take that and divide by strip length 4320/40 = 108 strips total.

      So actually it is more like 72 main section + 36 for the add-on section.

      For the first section you double the 90″ five times. Your first strip needs to be 2880 long. So that will take 72 jelly roll strips.

      For the second section you double the 90″ only four times. Your second strip needs to be 1440 long. So that will take 36 jelly roll strips.

      That should give you a quilt that is approximately 90×96.

      1. Thank you for helping me with this!

  23. Michelle, I’m afraid I do not understand the formula. If my end desired size is 90 x 96, would that be 72 strips for Section 1 and 16 strips for Section 2? I’m afraid I’m having a hard time comprehending this. Thank you.

  24. I want to make a small throw jelly roll quilt. I have some excess fleece I want to use as backing that is 48×60. Do you think I should do the standard jelly roll, baste, then cut off the excess and bind, or should I try to add some extra inches to my fleece? Thanks!!

  25. Am planning to make a jellyroll throw quilt for my sin and found your site to figure out how many jellyrolls to buy. I have BA degree from college with s minor in math. I can still do algebra and some calculus but quilting throws me for a loop. Thanks for your instructions.

  26. Am planning to make a jellyroll throw quilt for my son and found your site to figure out how many jellyrolls to buy. I have BA degree from college with a minor in math. I can still do algebra and some calculus but quilting throws me for a loop. Thanks for your instructions.

  27. I have purchased a pack of 24 2.5 by 44. Strips. I want to cut my strips in half before i sew them together so the patterns change more. What size backing will i need? I am wanting a baby blanket

  28. This page is absolutely wonderful. I will be making a (cut from my stash) “practice” quilt which will match the colors in our front room for the dogs bed. But then I’ll be making one in my colors for my twin bed. Woo Hoo! I do believe any questions I may have are already answered in the comment section. KUDOS TO YOU.

  29. I have many 1.75″ WOF strips…how do I figure for a jelly roll quilt….probably 60 x 80…Thanks

    1. Michelle ~ Wee Folk Art

      If your strips are only 1.75 inches tall and you loose a ΒΌ inch on either side for seam allowance, your strip rows sewn together would look like this…

      1 row = 1.25 inches tall
      2 rows = 2.5 inches tall
      4 rows = 5 inches tall
      8 rows = 10 inches tall
      16 rows = 20 inches tall
      32 rows = 40 inches tall
      64 rows = 80 inches tall

      So that gets you the height you want.

      If you want it 60 inches wide…
      64 rows x 60 inches wide = 3840 inch mega strip

      We initially rounded our 42 inch strips to 40 inches. I’m not sure how long your strips are… but subtract 1 inch from each strip for seam allowances and knowing that one strip will have to be cut in half at the beginning.

      3840 / Strip Length = Number of strips needed

  30. Thank you for all the info in this post.
    You have inspired me to try this.
    It sound like a lot of fun!!

  31. Math is not my strength! I like to use some of the strips for the binding. How many do I need to set aside before I start my jelly roll race? (So I have enough to go around the outside)

    1. Michelle ~ Wee Folk Art

      For a binding, you will need to set aside enough to equal the perimeter of your quilt. So the base quilt is 50x60in which gives you a perimeter of 220 inches. Divide that by the length of your strips and you will need about 5.5 strips. So set aside 6.

  32. Do you have a picture of the first quilt?

    1. Michelle ~ Wee Folk Art

      All the pictures I have are in the three posts I have done regarding the Jelly roll race quilt. Be sure to follow the links for the other two posts to see all the pictures.

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