Sunday, February 26, 2017

Round Bag Fundamentals + Calculator + Pattern + Tips



Click here to download my Round Bag Calculator (excel).
Note:  Fractions may not be view-able if using a mobile device.

Click here to download the Small Round Bag Pattern (pdf).
Print in portrait mode, and verify the 1" square on the printed copy is truly 1".

Tips for sewing round bottoms into bags:
  • Mark your seam allowance on the circle with a pencil so that you can verify that you aren't deviating off course. 
  • Mark the quarters of your bag and the side of your bag, and then check to make sure those marks line up when you are sewing.
  • Use a magnetic seam guide, or mark the needle plate of your sewing machine with a piece of tape, to help see the seam allowance when you are sewing.
  • When at the sewing machine, place the side of the bag on the bottom (against the feed dogs) with the right side facing up. Place the circle with right-side facing down. 
  • When sewing, hold the with your right hand.  Use your left hand to ease the circle so that the edges of both pieces of fabric line up at the seam allowance. Hold the circle at least 1/2” in from the edge to prevent bias stretching.
  • Stop sewing with your needle in the down position, lift your foot, and ease the fabric when needed to keep circle stitching smooth and to prevent puckering.   
  • You could also use pins to hold the side of your bag to your circle on the quarters or eights.


Do the math:

π = 3.14159….
D = Finished Circle Diameter
S = Seam Allowance
C = Cut fabric circle = D + (S x 2)
L= Cut length of the side of the bag = (D x π) + (S x 2)
 
Common Bag Sizes:
(In inches, all seam allowances are 1/2" inch).
D C  L
Finished Bag Size Cut Fabric Circle Cut Length of Side of Bag
4 5 13  9/16
4.5 5.5 15  2/16
5 6 16 11/16
5.5 6.5 18  4/16
6 7 19 14/16
6.5 7.5 21  7/16
7 8 23     
7.5 8.5 24  9/16
8 9 26  2/16
8.5 9.5 27 11/16
9 10 29  4/16
9.5 10.5 30 14/16
10 11 32  7/16
10.5 11.5 34     
11 12 35  9/16
11.5 12.5 37  2/16
12 13 38 11/16
13 14 41 13/16
14 15 45     
15 16 48  2/16
16 17 51  4/16
17 18 54  7/16
18 19 57  9/16
19 20 60 11/16
20 21 63 13/16


20 comments:

  1. Awesome blog. I enjoyed reading your articles. This is truly a great read for me. I have bookmarked it and I am looking forward to reading new articles. Keep up the good work!
    leather handbags on sale

    ReplyDelete
  2. This blog has been a tremendous help for my bagmaking. I love the circle calculator! Now I’m hoping to branch out to ovals. I found a site that does the math for me, But I don’t know how to figure in the seam allowances.

    For example, I have a strip of fabric that I’ve quilted that measures 30.5 inches. 12.2” and 6.3” are the length and width given by the calculator. Since I’m quilting, I’m using a 1/4” SA, and I don’t want to cut my strip, because the quilting needs to be symmetrical. Do I just cut accordingly, or do I need to change the l & w of the oval? Thanks! (I flunked geometry in high school. Wish I could go back and try it again.) ��

    ReplyDelete
  3. Nice to be visiting your blog again, it has been months for me. Well this article that i’ve been waited for so long. I need this article to complete my assignment in the college, and it has same topic with your article. Thanks, great share.
    Round Purse

    ReplyDelete
  4. Some thing advanced for example drawing on a smiley face on the test will probably capture your buyer's interest. They may discover that it's cute as well as keep in mind you . In addition, it can place your purchaser in a joyous and ample feeling. If a client is fulfilled and joyful it's possible he'll provide you a bit of server hints.You can use this tip counter through which you can easily came to know split the tip and all the bill amount among the given number of people.

    ReplyDelete
  5. This is great.... it helped me a lot with my sewing projects. Thank you very much for sharing that with everyone.

    Have a great day.

    ReplyDelete
  6. This was so incredibly helpful. I've been making Yoga bags and had switched to a box bottom because I could not get the size for the circle to work out properly. You have made it so easy and the one I just did is perfect. Thankyou!!!

    ReplyDelete
  7. The issue is finding an excellent pair of replica shoes, from a source that may be trusted. To find more info about Yves Saint Laurent purses, browse this site.

    ReplyDelete
  8. hi,

    Can you please share your email ID as I have few queries about camping tents sewing?

    Regards
    Shalabh

    ReplyDelete
  9. Thanks for share this tips.Every calculator guideline known is important.

    nika-talana

    ReplyDelete
  10. I have a question about this pattern and calculations. Following the instructions with half inch seam allowance, my circle is always too big. As the chart says we are to add one inch to our circle for ‘both sides’. But say a 6 inch diameter, why not use the 6.5 inch instead of the 6. (This worked for me) but still using the 19 14/16 length of bag. The printout is great though I am either missing something or the numbers are wrong (which I question for certainly I wouldn’t be the first to notice this AND you really ‘seam’ to know what your talking about.). Are we supposed to do one inch seam on the circle when sewing?

    Thanks jellyfish. Jivako

    ReplyDelete
  11. Great Blog, Buddha Udyog is the best non woven bags manufacturers in Delhi. Want to purchase non woven bags so I highly recommend them because they are offering at a stipulated price with great quality.

    ReplyDelete
  12. Do you have calculations for making a box tote I've been trying to figure out the formula for this for years Thanks.

    ReplyDelete
  13. I can't access the PDF because you need to give permission to the people that want to access the document.. I requested the permission as the application asked me, but I haven't got it yet. I think it has to do with the location you saved to file to and/or the restrictions you put for the file to be accessed.

    ReplyDelete
  14. Can't access pattern or calculator.
    Has anyone been able to do that???
    Please help

    ReplyDelete
  15. Wow this is exactly what I need to make a round cover for my metal water bottle! Thank you so much, I have been guessing, and not doing such a great job.

    ReplyDelete
  16. been around for a loong time at the forums, have used this before to make stuff sacks for hammocks of course but am makin some fantasy larp style pouch and needed a round one and remembered your tutorial! forgot to add in for the flatt felled seam on the first one and couldnt figure out why i had puckering lmao. great tut, much thanks!!!

    ReplyDelete