How To Design Your Own Hat (Part 1: The Basics)

One of the main reasons I started designing my own hats was because I struggled to find crochet patterns that didn’t look like those crocheted Barbie toilet paper covers my grandmother had.
When I first started, it was complete guess work.  I didn’t know about even increases or flat circles and crocheted everything in a UK Treble/US Double crochet. Patterns evaded me (and still do to some extent).  I would always lose count of stitches and never knew where the designer intended for me to put my hook. My hats looked more like something out of the hyperbolic reef project, rather than a garment.

About 3 years and countless hats later, I feel relatively confident in my ability to make a hat to fit a head. But even now, I remain baffled by the lack of readily available information on how to design your own. These type of instructions are much more prevelant in the knitting community, Elizabeth Zimmerman being the classic example. It was reading her Knitters Almanac that really taught me how to design.

To save others the frustration I have gone through I thought it would be useful to lay out my process for designing a very basic beanie style hat.

To keep things simple, I am laying out the posts over a couple of days.  Today, I will just give an overview of the general principles and then tomorrow, we will look a the nuts and bolts of hat design.

Beanies are generally the easiest of hats as it follows a very simple pattern:

- increases are worked over a flat circle to the desired diameter and then,

- the increases stop and the hat height is built up using rounds of the same number of stitches as the last increased row, or “worked even”.

Have I lost you? Let me explain.

Remember geometry class and those endless problems involving pi?  Well, contrary to what I told my math teacher about geometry being useless in ‘real life’, it actually comes in handy when making a hat.
Very often, you will know (at least roughly) the circumference of your recipients head.  Even if you haven’t measured, there are a variety of guides that give you the basic size range for head sizes. Hat sizes are about 1-2 inches smaller than the head size and have heights that correspond to circumference. No matter where you look, they are pretty standard.  My hats are generally sized as follows:

Age	Head Size	Hat Size	Hat Height	Flat Circle Diameter
0-6 months	13 – 15in	12 -14  inches	4.5 – 5 inches	4 inches
6-12 months	16 – 19 inches	14 – 18 inches	5.5 inches	4.5 inches
1 – 3 Years	18 – 21 inches	17 – 20 inches	6.5 inches	5.5 inches
4+ years	20 – 22 inches	19 – 21 inches	7.5 inches	6 inches
Women	22 inches	20 inches	8.5 inches	6.5 inches
Men	23 inches	21 inches	9.5 inches	6.75 inches

The range of measurements in sizes is usually covered by making a hat to the smallest size in an age range, quite simply because hats stretch, some more than others. Materials like wool are stretchier than cotton and certain stitches stretch more as well.  I like UK Half Treble/US Half Double Crochet for most hats as it is a good balance between creating a nice solid material, with a nice stretch in it.  Longer stitches, such as UK Treble/US Double, and shell stitch have a lot of stretch.  UK Double/US Single crochet is pretty tight, but does create a lovely, even fabric.
But really, the type of stitch you use is largely irrelevant. You need to use that stitch to increase steadily in a flat circle, until its diameter will give you a hat of the correct circumference. How do you know? Well, its that good ol’ geometric equation where

Diameter (the distance across the circle) = Circumference (the distance around the circle)/pi

You’ll see in the table above that I have calculated the diameters of the flat circles for most hat sizes. However, if you know the head size you are making for, you need to:

- Subtract 1.5 inches from the head circumference to get the hat size

- Divide the hat size by 3.14

The resulting figure is the diameter. Once you get your flat circle measuring something akin to the correct diameter, stop increasing and just crochet in the round until your hat is the right height. You can always use a balloon blown up to the right head size to check your sizing if the recipient isn’t readily willing and/or available (also balloons are great for blocking beanies.)