How to Properly Size Hats HUMPDAY TUTORIAL!

After much sweat, blood, and tears...I have finally finished my hat sizing chart. For those of you that crochet (or knit!) hats on a regular basis, you know how difficult it can be to accurately size a hat. Sometimes it's the difference of ONE stitch that can totally throw the whole size off!

I have concocted a sizing chart, based on using worsted weight yarn, with the option of 2 different size hooks. I hope this chart will help you with your frustration. I know it has definitely helped me. I am no longer pulling my hair out and frogging every single hat! :)


By using a simple circumference calculator (found here!), you can accurately determine the diameter and circumference. All you have to do is make your circle and measure across the center. This is your diameter. Use the calculator I linked to, or just multiply by 3.14 (remember geometry class?). This number is your circumference. Then you just have to adjust the length accordingly (obviously smaller hats will have less rows, and larger hats will have more rows). I generally use half double crochets, and find that smaller hats have 18 rows, longer hats have 20. 

I know there are other hat sizing guides out there, and definitely some that are better than this one, but hey... the internet can never have enough information right??? 

Hat Sizes with H (5mm) Hook
STITCHES	CIRCUMFERENCE (in.)	DIAMETER (inches)	SIZE
50	16.5	5.25	18-24mo
52	17.2	5.5	2-3T
54	18	5.8	4-5T
55	18.8	6	Child
60	21	6.6	Small Adult

Hat Sizes with I (5.5mm) Hook
STITCHES	CIRCUMFERENCE	DIAMETER	SIZE
40	12.5	4	Newborn
41	13.8	4.4	3-6 month
42	15	4.75	6-9 month
43	16.2	5.15	12 month
50	20.5	6.5	Teen
55	24	7.5	Large Adult Male