How many stitches does my crochet hat need to fit? Dora’s ultimate guide to accurately sizing a crochet hat
Like many crocheters, one of the first things I ever made to gift was a hat. The owl hats from Repeat Crafter Me to be precise. Only I got the sizing all wrong because back then I didn’t understand that the most common yarn in the US is worsted whereas here, in the UK Double knit seems to be more popular.
It was a valuable early lesson and the beginning of my curiosity about what I now understand to be gauge.
I wanted to avoid making that mistake again so started making a record, scribbled in the back of my crochet note books, of the hats I made; what the finished size was, what size hook I used and how many stitches there were in the finished circumference.
I first opened my Etsy shop, for a brief spell in 2013 and I must have made 30 minion hats that Christmas, and I quickly learned that making finished objects was not for me! However, this was a valuable exercise in adding data to my little hat size chart.
I had found so much variation in the hat size charts and size guides I looked at on the internet that I figured I would use my own data which I knew worked for my crochet style.
Ever since I started this blog, I knew that I wanted to publish this information, so that others could save themselves the time. I envisioned a table with hat size / age: hook size: and the final number of stitches needed before you stopped increasing to achieve the right circumference. But I knew that something was missing, I had to account for yarn weight somehow to make this accurate and I wasn’t sure how to do this so I set the idea aside in favour of other projects.
Until today – it came to me in the shower and feels so blindingly obvious now that I don’t understand why I didn’t think if it before!
The answer is maths!
(but don’t worry, I’ll do it for you!)
This week, I’ve been grading a sweater pattern in kids sizes and had a panic that the head hole wouldn’t fit over the head of a 2 year old, so I dug out some head size charts to find out. I used Pi x d (where d = diameter) to work out the circumference and matched that to the kids head size to check (it should be good!).
Well what does that have to do with hat sizes? I hear you ask. Well, I’ll tell you!
In the shower this morning, where I do all my best thinking, I was questioning whether I had done the maths right, was it pi x d or Pi r squared? My A Level maths was wavering!
So there I was thinking about head circumference and this idea of hat sizing came back up to the surface. And I remembered that all I needed to size a hat was the gauge measurement and the required head circumference. It doesn’t matter what hook size or yarn you are using because, as I’ve learned through my many posts about it this year, Gauge is the BOSS!!
So I’m sitting here in my towel writing this out before the idea disappears again like a dream does on waking. I’ve set aside what I was meant to be doing this morning and go and do some maths… If it all goes to plan then below you’ll find a single table with the ultimate guide to how many stitches you need to increase to to make a hat of any size.
But first some context
Here are a few assumptions I’m working with.
This table was worked with hats worked top down in the round in mind. Though there is no reason it wouldn’t work for other styles.
For those newer to making hats. The classic way to work a top down beanie is to work a flat circle from the centre out, increasing by the same number of stitches each round. Then you stop increasing and work in rounds until the hat curls round and reaches the desired length.
There are a couple of blog posts / charts which tell you to increase until your diameter reaches X cm / inches and then stop increasing and work the same number of stitches. These are excellent guides, but I always struggled with that method because so often the required diameter fell between two rounds – which would often make all the difference.
This method uses a similar principal but takes it a step further. You’ll start knowing the final stitch count you need and can then work backwards with your increases.
These numbers aren’t going to be nice neat multiples. My recommendation would be that you work to the nearest multiple and then just wangle it on the final increase round.
If you’re designing at hat then you will also need to think about things like pattern multiples, but if you’re just working with a single stitch then it’s easy to add a couple of stitches here or there if the number isn’t a multiple of the number of stitches in your magic ring!
It’s worth noting that the multiple and stitch you use will dictate the shape of the crown. Those maths are for another post though! (which I will follow up with soon!!)
Okay so here it is….
How many crochet stitches do I need to make my hat fit?
I know it’s probably not the easiest to read on a screen so if you would like a larger PDF with more step by step instructions on how to read the table, then sign up to my mailing list here and it will be delivered direct to your inbox!!
Note that the head size and the hat size are listed separately because you always want to make your hat an inch or two smaller than the head so it stays on!
To read the chart, simply select the age, head circumference or hat circumference you want to make from along the top, then choose the gauge your stitch pattern uses (because you have done a gauge swatch of course!) down from down the side and read down and across to find the number of stitches your final decrease round needs to achieve the chosen hat circumference.
If you have never made a gauge swatch before, you can learn how to do so (and why you should) here.
The row detailing diameter of the crown is an additional guide and does not relate directly to the gauge measurements. This is my version of other guides that are out there which suggest you work until the crown is a certain diameter before you stop increasing.
I hope you find this information useful. If you want a more detailed explanation, the PDF containing an A4 version of this chart also includes a worked example.
Happy Hat Hooking!