View Full Version : how to know what size circles to use

August 23rd, 2012, 01:51 AM
Hello ladies!

I was hoping you could help me out. I'm wanting to make a tube like pillow. A round tootsie roll type thing. But instead Iwant a flat ends, so I will be using circles at the ends.

My question is when I make the tube with one rectangle fabric piece by making a seam at the top which gives me a tube but my problem is how do I know how big the circles at the ends need to be? Hope that makes sense...


August 23rd, 2012, 02:19 AM
I know exactly what you are talking about. Once you have the diameter (distance from one side of the circle to the other) you will be able to cut your circle. You will be able to do this after you make your tube. Lay the tube flat and measure across and that will give you the diameter of your circle. If the diameter is 15 for example, using a compass, draw your circle putting your compass point in the center and your pencil 7 1/2 inches out. Once you draw it, your diameter will be 15. BUT REMEMBER, You will need to add your seam allowance to the 15 before drawing your circle. Get it?

August 23rd, 2012, 02:51 AM
I think so, thanks!

August 23rd, 2012, 02:59 AM
Give me 5 mins and I'll send a rough diagram

August 23rd, 2012, 03:04 AM
Ok, here is the diagram. Sorry its messy, I just wanted to get it to you quick. Let me know if you need any more help.26741

August 23rd, 2012, 03:32 AM
Thanks, that helps...

Now I know I need to add seam allowance, so my question would I add that to the width of the tube (short end) and add for example 1" to the 15 and that it would be then 8" instead of 7 1/2"... Which should be 16 instead of 15, right?

August 23rd, 2012, 03:43 AM
I used 15 as an example. I don't know what size pillow you are making, therefore I don't know the measurement. Make your tube whatever size you want it, you will have to add your seam allowance to the ends of the tube so your finished length is what you want it to be. Once your tube is made, then measure the opening so that you will know what size to cut your circle. So, for example if your tube, when laying flat, measures 15" wide (again, only an example) then you will have to make your circle 16" in diameter to cover your seam allowance. Actually, I think you will still only have to add 1/2" and not a full inch, making the circle 15 1/2" in diameter. Now if you want your pillow to be 25" long for example, you will have to cut it 25 1/2" long to allow 1/4" seam at each end. Im still up so let me know if you need anything else. If you want, when you make your tube, I can help you to do your circle, just let me know

August 23rd, 2012, 04:21 AM
Nope I think I understand now. Thank you so much, I appreciate it...

Going to bed before I start walking for the sewing room... 3:20am here, lol

Again, thanks!


PS. I will let you know how it goes. :)

Jean Sewing Machine
August 23rd, 2012, 07:08 AM
I can't remember my 5th grade math where we learned how to figure diameter of circles, but i'm not sure you found the diameter by measuring across the flat tube. You actually found the perimeter or circumference., 15"times 2=30", that is the perimeter. That's where my limited math skills fail me, not knowing how to figure the diameter from that number. I'll look it up and post.

This site says it can help you figure it out. Give it a try. Remember to add your seam allowance before you cut.

Wow, I just tried it and it is great! Measure the length of your fabric that is going to make the tube, Subtract seam allowances, or measure as the above forum member suggested, times 2. Plug in that number, it gives you the diameter, easy-peasy!

Sandy Navas
August 23rd, 2012, 09:49 AM
Jean is correct - whatever the circumference of your tube - therefore how long you cut your fabric before sewing the tube, and divide by 3.14 (or pi) - to get the diameter . . .

So, if you sewed WOF into a tube - assuming 42 inches, you would need a circle on the end of approximately 14 inches.

August 23rd, 2012, 12:48 PM
OMG, CJ make sure you listen to Jean and Sandy. I totally forgot a step in the math that I gave you, I'm so sorry. I knew I shouldn't have been doing anything that involved math at that time of the night. Funny cause when I went to bed at 3:20, I kept thinking something wasn't right. I'm really sorry!

Claire Hallman
August 23rd, 2012, 12:53 PM
You need to use a larger seam allowance than 1/4 for home dec fabrics and to give you a little wiggle room, a half inch is normal for pillows and 5/8 wouldn't hurt.
If you want your pillow to be full then you need to make your cover a bit tight so the filler totally fills the cover completely.

August 23rd, 2012, 03:08 PM
Unfortunately, I suck at math so now I am a little confused... lol

Jean Sewing Machine
August 23rd, 2012, 06:37 PM
If you tell me how big you want the pillow, I can help you out.

August 23rd, 2012, 11:13 PM
I'll get back with you when I know that... Thanks

August 24th, 2012, 04:08 AM
Just so you guys know what I am trying to make is a neck pillow. I do have a pattern for the regular dog bone shape, but not a big fan of the very end part, so I was hoping to make a circular neck pillow with flat ends (if that makes sense?)

I wasn't able to find a pattern to help me, so I was trying to go off on my own, but stuck with the circles to close the end. I know there are the candy wrappers type look, but in my opinion that isn't a buy kind of style if that makes sense...

So that's what I am trying to figure out.

Thanks.... :-)