Making a perfect (and easy) circle

Do you ever need to make a circle and then wander the house looking for something round you can trace that’s just the right size? And you get completely bewildered about how to actually create a perfectly even circle because you can’t freehand one? Oh, that’s just me? Well, still, I thought this little concept warranted its own breakout tutorial. I’ve mentioned it before a few times, including last week’s bolster pillow tutorial. 

One way to draw a circle, if you remember geometry class, is to use a compass. You know, those little adjustable things you stick a pencil in and then put the pointed end in the middle and try to draw a circle with the pencil part. And it never comes out even. Ever. You feel like you could be in one of those infomercials where people try to do something simple but it always results in them completely spazzing out and looking ridiculous. But, thank goodness, there’s a solution! For your circle, it’s this easy tutorial. 

But wait, there’s more!

It’s totally free. Send no money now. Or ever!

Let’s talk math

Let’s do a little geometry review. This part is for the projects where you need to determine how big your circle needs to be. If you already know, go ahead and skip this part and go to the easy part below.
Say you’re making something with a round end, such as a yoga-mat bag or a bolster pillow. How big should your circle be, exactly?

Some key terms:

Diameter (D) = distance across the circle from side to side through the center.

Radius (r) = distance from center to one side of the circle, or 1/2 of the diameter.

Circumference (C) = distance around the outside edge of the circle.

Pi = 3.14 = it’s the ratio of a circle’s circumference to its diameter

C = Pi x D

D = C/Pi

OK, so let’s do an example. Let’s pretend you’re making a bolster pillow, which is essentially a tube with circles on either end. Say in the picture below that A = 30″ and B = “25.”

You sew your A sides together to form your “tube” and you have two round ends, B, that are 25″ around. That’s the circumference of your end circles. So what is the diameter?

D = C/Pi
D = 25/3.14
D = 7.96″, or basically 8″.

Radius is half of that, or 4″. So you then proceed with the steps below using your calculated figure for the radius.

 

The process

Start with a big piece of paper and fold it in half so the fold is at the bottom.
Fold it again so there is another fold on the right side. Now, your bottom right corner is a double-folded corner.
From that corner, take a ruler or tape measure and measure the radius of your circle along one straight edge. Make a mark (my radius is 12″).
Repeat on the other straight edge.
Line up one corner of your ruler on the folded corner and make another mark the length of your radius. I am lining up the right edge of the ruler with the corner, so I’m only making marks along the right edge of my ruler. Obviously, if you marked on the left edge, too, it would not be accurate since that edge is not aligned with the corner.
Continue in small increments all the way across to form an arc. The tighter your dotted line, the easier to draw in the next step.
Connect the dots and form an arc from edge to edge. I also drew the radius and labeled it, but that’s not necessary. Just for example.
Cut out along that arc, ensuring that the paper layers are smooth and lined up.
Open it up and you’ve got a big circle 24″ across. Of course, this works for any sized circle.