Making and designing your own crochet hats is lots of fun but it can also be very challenging. It can be very difficult to get a hat just the right size, even if you are following a pattern. While there is no magic wand for getting the perfect fit, I have discovered a simple formula that works MOST of the time.
I start my hats at the top (crown) and work my way down to the brim. Depending on the pattern and style of the hat, I usually work in the round. (Like a spiral) To make the top of the hat I increase in each round until I have a flat plate like piece. When the crown of the hat is the right width I continue working in rounds without increasing the number of stitches. I keep going until the hat is the right length. (See links below for size charts)
I never expected to actually use any of that geometry stuff I learned in high school but to my great self satisfaction I worked it out.
The Formula (working out how big your crown needs to be)
head circumference - 1.5 / 3.14 (pi)
example circumference = 19"
19" - 1.5 = 17.5" 17.5/3.14 = 5.5"
So you create a circle and continue until it measures 5.5 inches across. Then you continue working and wa la, you have a hat.
Bev's Country Cottage
A great site with all sorts of size charts.
Slugs on the Refrigerator
A fantastic tutorial on sizing hats.
