Crochet hat sizing: A guide to crocheting hats that fit

Like many crocheters, one of the first things I ever made to gift was a hat.

It was one of the owl hats from Repeat Crafter Me to be precise. Only I got the sizing all wrong because back then I didn’t understand what yarn weights were all about.

It was a valuable early lesson and the beginning of my curiosity about what I now understand to be gauge.

Crochet Hat Size Guide – What’s covered in this post

This post explains what I have learned about sizing hats over my years as a maker and designer and includes my complete guide to hat sizing, for any yarn wight and hook size.

The table at the end will tell you how many stitches you need to crochet around the circumference of your hat, to achieve a specific size.

I encourage you to read the whole article (about 10 mins) so you can understand where these figures came from and how to best use them when making your own crochet hats.

This guide focuses on the circumference of the finished hat and does not offer guidance for hat height.

There are plenty of hat height charts on the internet which offer a rough guide to hat height. However, I think that the height of the hat depends so much on the style that it’s not something I think you can easily standardise.

That said, I have included a ‘standard’ crown to base of ear measurement though as I think this is valuable information when crocheting a hat. It gives you a minimum hat height size, which is a good place to start!

The circumference measurements are based on Woolly Wormhead’s hat size guide, the Craft yarn council standards and a variety of other hat sizing guides from the internet

I do not address hat heights in this post because it is dependent on the style of hat you want to make, but the Woolly Wormhead sizing guide has some standard crown to base of ear measurements which you may find helpful.

How I size crochet hats

After I understood my classic yarn weight mistake, I started making a record, (scribbled in the back of one 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.

Early on in my crochet career, I tried out selling finished objects. Back in 2013, I must have made 30 minion hats that Christmas and I quickly learned that making finished objects to sell was not for me!

However, this was an incredibly valuable exercise in learning about hat sizing and 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 (i.e. my gauge).

My table included hat size / age, hook size, and the final number of stitches needed before you stopped increasing to achieve the right circumference. This was all based on typical acrylic DK yarn.

When I started Dora Does, I knew I wanted to help others avoid the same mistakes I had made by sharing this information, which had become so valuable to me. (It was how I sized my first ever hat pattern, the Christmas Pudding Hat).

But I knew that something was missing from my data. 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.

Ever since I started Dora Does, I knew that I wanted to publish this information, so that others could save themselves the time.

Until I had a revelation…

The answer came to me in the shower (where I have all my best ideas).

So often you find the solution to a problem when you’re looking at something one step away from it! And it feels so blindingly obvious now, that I don’t understand why I didn’t think if it sooner. But that is the power of experience!

The answer is maths (and gauge)…

But don’t worry, I’ll do the heavy lifting for you

That week, I was grading a kids sweater pattern and was worried about whether it would easily fit over the wearer’s head. I had been looking at head size charts to check that the width of the neckline was larger than the diameter of the child’s head.

So there I was in the shower, questioning whether I had done the maths right (was it pi x d or Pi r squared? My school maths memory was wavering), thinking about head circumference (like you do), when the idea of hat sizing bubbled up from my subconscious where it had been languishing.

I realised that all I needed to size a hat was the gauge measurement and the required head circumference. Those worries about needing a different chart for each yarn weight were unfounded.

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… it’s about gauge.

Gauge is the key!!

So I put the pattern I was working on to one side and set about creating a new table showing how many stitches you’ll need for x gauge to make a hat measuring y circumference.

That is what you will find in the chart below.

This was the style I had in mind when coming up with this information, but it will work for other construction styles if appropriately adapted.

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 approach of measuring the flat crown also doesn’t account for hats which aren’t made with a flat circle. If your hat has a little more shape, a pointy crown maybe, then your circle is not going to be flat, and this method may lead you up the garden path.

This is why I prefer to use gauge.

Once you’ve done your gauge swatch, you can start making your hat, already knowing the final stitch count you need.

Then you just need to work backwards to decide how to achieve it with your increases (assuming you’re using the flat circle method discussed earlier).

This post about how to calculate increases in the round may help you work out how to space your increases.

The final stitch count you need to achieve won’t always be nice neat multiples of the number of your stitches in your magic ring. I get around this by working increasing my the same multiple until the numbers don’t add up any more, than working just enough (evenly distributed) increases in my last increase round to achieve the number I want.

However, if you’re working with a stitch multiple for your crochet stitch pattern, then the way you increase will require some additional thought.

The chances are, the number of stitches you need for your finished circumference are not neatly divisible by your stitch multiple.

In this situation, and because a hat should be smaller than the head it is meant to fit (i.e. have negative ease) then I would always tend to go with fewer multiples rather than more.

I recently learned from Woolly Wormhead, who is the master of knit and crochet hats, that she uses around 12% negative ease for her hat sizing. That is, the hat should be 12% smaller than the head it is designed to fit.

I also use the the 2 inch rule (i.e. make the hat 2 inches smaller than the head), to work out my final hat size.

However, the amount of negative ease will depend on the stretch of the stitch pattern you’re working with. This is a variable that is hard to accommodate and is something you’ll need to assess when making.

For example, I worked with much more negative ease in the fisherman’s winter beanie because the fabric is so stretchy.

Stitch pattern, stretch and hat sizing

When you’re making a hat, you’ll need to think about the properties of the stitch pattern you’re using.

As already mentioned, some stitch patterns have a huge amount of stretch and others very little, but on top of this, you’ll want to think about elasticity. Does the fabric bounce back?

This amount of stretch will impact the amount of ease you want and therefore the final circumference size you want to make.

This is especially important for the brim if it is the part of the hat that is securing it on the head.

For a stitch pattern with very little stretch, you want a smaller amount of ease (so a larger circumference), whereas for stitch patterns with a lot of stretch, you’ll want to make the hat smaller.

All the sizes here are just a guide ultimately. You may need a little trial and error here to accommodate a very stretchy or inflexible crochet fabric.

Crochet ribbing and hat brims

The part of a typical beanie or bobble hat that really needs to fit is the brim. This is the area where you need that negative ease to keep it on your head.

Crochet ribbbing is used a lot on crochet hats as tends to have more elasticity than other stitch patterns. So no discussion of hat sizing and fit wold be complete without touching on this area.

I’ve been experimenting recently with many types of crochet ribbing, and have put together a 2 part directory sharing all the different ways you can crochet a rib effect and comparing the elasticity and stretch of each method.

I have included a video in each post showing how each type stretches and bounces back. This is particularly useful for thinking about which type of ribbing you might want to add to a hat. The more elastic the better for a longer lasting hat.

Part 1 of the rib stitch directory looks at crochet ribbing using the back and front loop only methods. (View it here)

Part 2 looks at crochet ribbing using front and back post stitches (view it here)

Furthermore, a while back I created a written and video tutorial showing how to easily add ribbing to a top down crochet hat without sewing. This can be used for most styles of vertical ribbing. Some adaptation may be required but the principle is generally the same.

Okay, now time to get to the data!

How many crochet stitches do I need to make a hat fit?

I have created 2 tables to help with your hat sizing.

The first, below, is a rough guide to head sizes for different age groups. This is a guide only and it is why it is given as ranges.

In older versions of my hat size guide, I gave specific values, but the more I research head sizes, the more variation I find in sizing. So I settled on a range as a starting point for you. Ideally you will want to measure the head you are making the hat for and then deduct the ease to decide how big your finished hat will be.

I have left in the flat crown diameter measurement in the table as an approximate reference point only.

Once you know how big you want your hat to be, the second table comes into play. It shows you how many stitches you need to work, based on stitch gauge (listed down the left column), to achieve a specific finished hat circumference (listed along the top).

To read the chart, simply select the finished hat circumference you want to make from along the top, then choose the gauge your stitch pattern uses (because you HAVE made a gauge swatch!) from down the side, and read down and across to find the number of stitches the body / brim of your hat needs to achieve the chosen hat circumference.

Note that because of the inconsistency in hat sizing for different age groups, I have removed this aspect from the stitch count table and given size options in 2.5cm / 1 inch increments.

If you want to work out the number of stitches for a measurement not listed, this post explains how to calculate your stitch count for any measurements based on gauge.

Assumptions and notes

As you look at the data, there are a few other assumptions I’m working with that you’ll need to know.

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 where the stitch gauge is used for the circumference.

If you are working a hat construction which is side to side, you will need to switch stitch gauge for row gauge to use the table (as the rows are what form the circumference).

If you have never made a gauge swatch before, you can learn how to do so (and why you should) here.

I hope you find this information useful.

Happy Hat Hooking!

Dx