Pi Recipe

For you that know me well, you know that isn’t a spelling error. I’m really not one for cooking or baking, and no one wants a recipe for Pie from me.

But when it comes to recipes for crocheting creativity that are related to applied geometries, that is a whole nuther story.

Some of you may remember that old equation from your school days of  “Pi R square” (and the standing joke was, “No, Pie are Round”).  Pi is literally the secret to understanding circles, and the secret to making hats that fit perfectly.

Baby Doll's New Hat

Pi = 3.14  in reality it is a much longer decimal than that.  But taking the number to 2 decimal points is more than sufficient for our purposes.  In fact, with a little adjustment to our calculations, taking away the decimals all together works too.

I love making hats as gifts and often they are my “go-to” project when I just need some instant gratification crochet. I don’t know that I have ever made a hat from the brim up. I much prefer the ease of working with top down construction.

My favorite thing about working top down is how simple the foundation is. Start with an adjustable slip knot, then chain a couple stitches, work the first round of stitches into the first chain…Voila! You are off and running. Crown down construction also allows for some really simple decorative stitch work for the brim.

There are lots of fabulous hat patterns out there, and you can make sure that your hat fits yourself or your giftee perfectly by using some simple math. 

Baby Doll's Head Circumference Measurement

You are going to need a couple of measurements.  You need the circumference of their head, which means the distance around their head measured at eyebrow level. 

Baby Doll's Hat Depth Measurement

And you’ll need the “depth” measurement, which is referring to the length of the finished hat from middle of the crown to the edge of the brim.  Being I like my ears covered by my hat I measure to the bottom of the earlobe.

Target Diameter Measured

Baby Doll’s head circumference is 17.5 cm and her “depth” measurement is 6.5 cm.  So my calculation for figuring out how big to work my beginning circle is: 17.5 divided by 3.14 = 5.57 cm. Which I round down to 5.5 cm.

If you are making a gift hat and can’t measure the recipient’s head there are a couple of online sites that  have some helpful measurements for averages.  TotToppers, Wooly Wormhead,

Some other things to consider when personalizing a hat are preferences of the wearer: how snug they prefer their hats to be, if they want the hat to cover their ears, if they like extra coverage over their ears.

Typically you want a hat to be a bit smaller than the head circumference.  This is called “negative ease”.  Negative ease depends on the fabric of the finished hat (or garment) to have some stretch to it. The amount of stretch needed is dependant on how much negative ease is planned for.

Target Depth Measured

Once I achieve my target size for the diameter of my circle I will then continue working rounds without increases until I reach the depth (or length) that I want.  If I am just winging the depth, I’ll stop when I think I am nearing the length I want. Then flatten the hat so the center of the crown is halved I measure the length.

Now it’s your turn.  Using a hat pattern you love see if you can make a hat that fits you perfectly. Or try winging a hat using your favorite stitch in the round.

6 thoughts on “Pi Recipe

  1. WOW! What a GREAT tutorial! Thanks! I have a very small head and most of the hats I have made are always too big for me. I try going down a hook size which has worked some, but having this formula will be a great way to only increase to that certain point in the pattern and then stop. Can’t wait to try it out.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.