Crochet hooks in different shapes and styles

Why Crochet Hook Size Matters (And How to Choose the Right Hook)

Crochet hooks come in different shapes and sizes. But sometimes, hooks of different sizes can look so similar to each other. You might find yourself wondering, does hook size really matter? And if you lost or misplaced a hook, can you use one hook in place of another? 

Crochet hook size matters because the size of the hook determines the size of the stitch. The size of the stitch affects how big your project will turn out. Different hook sizes can also affect how thick and stiff or soft and drapey the resulting fabric will be. Hook size, yarn weight, and tension all combine to determine these outcomes. 

Hook size can mean the difference between making a sweater that’s so small it only fits a doll, or that same sweater turning out so big, it can fit three of you. 

Larger hooks generally work best with bigger weights of yarn. Smaller hooks generally work best with thinner weights of yarn. 

Not all hook sizes and yarn weights are meant to go together. For example, a tiny steel crochet thread hook isn’t going to be able to crochet with a thick rope 50 times its thickness, because the hook is too small to even grab the rope. 

Generally, a crochet pattern will state what hook size it was designed for, which you should aim to use. 

If the pattern doesn’t say, check the yarn label for the recommended hook size. 

Hook Size Affects Stitch and Project Size

Here are a series of hats made with the same yarn and pattern, but different hook sizes. 

The same pattern and yarn yield different sized hats depending on crochet hook size

You can see that the smaller hook yields a smaller hat, and a larger hook makes a bigger hat. 

When you have a loop of yarn on your hook, the size of that loop of yarn depends on the size of the hook.

Also, when you yarn over and pull through the amount of yarn you grab also depends on the hook size. The bigger the hook, the more yarn you grab. 

In general, the thinner the hook, the smaller the gaps between the stitches, and the tighter the stitches are against each other. 

Demonstration of hook size determining size of loop on hook and therefore stitch size

The hook on top is size H-8 (5.0 mm) and the hook on the bottom is a size N/P-15 (10 mm).

What Happens If You Use a Bigger Hook? 

If you use a bigger hook than the pattern calls for, the finished item will turn out bigger. Your stitches may be looser, which can cause gaps to appear in the fabric. This may not be a big deal if you’re making a blanket, but it can be a big deal if you’re making a sweater. 

If the new gaps in the fabric are large enough, the project may drape more, and end up being more soft, and less stiff. This may or may not be what you want. 

If you’re making a basket whose walls are supposed to stand up on their own, then a less stiff fabric may mean droopy looking sides. 

But if you’re making a cardigan and you are aiming for a cute oversized, fluid look, then a larger hook may be fine. Just note that the project will often get larger in every direction – longer and wider, which might not make for attractive looking or warm sleeves. 

Lastly, if you go up a hook size, you may run out of yarn faster, since more yarn will be consumed to make bigger stitches. You may want to make sure you can get more yarn before you commit to switching hooks. 

What Happens If You Use a Smaller Hook? 

If you use a smaller hook than the pattern calls for, the finished item will turn out smaller. Any gaps in the project may shrink or disappear altogether. 

Depending on the project, this may or may not be a good thing. 

If you were aiming to make a lacy doily, smaller gaps may hide or mask the doily’s delicate and beautiful design. 

If you were making a blanket, then hook size can affect how well your blanket keeps heat in. Gaps in a blanket help keep you warm by trapping warm air, while also allowing for some air exchange, which prevents you from overheating under it. 

Using a smaller hook may also mean the fabric comes out less drapey, and more stiff. For scarves and blankets, this may lead to a less snuggly and soft experience. A stiff shawl may not be able to show off its design as well. 

For clothes, this may mean the garment may turn out less form fitting, less comfortable, or less breathable. 

For dishcloths and washcloths, a stiffer, less malleable cloth may mean it’s harder to clean in small nooks and crannies. 

If you’re making a toy, going down a hook size can help because the resulting thicker fabric means that the toy will hold its shape well, and the smaller gaps means stuffing is less likely to show through. This is why many amigurumi patterns that use worsted weight yarn actually call for small hook sizes, such as a US E/4 (3.5 mm) hook even though the yarn label recommends a US H/8 (5.0 mm) hook for that type of yarn. 

Factors to Consider Before Changing Hooks

Does the Finished Project Have to Fit Or Be a Certain Size? 

Getting the right hook size is the most important for things that have to fit something else, like clothing. This includes sweaters, bikinis, dresses, hats, and socks. 

You don’t want a hat that ends up so big it covers your face. And you don’t want to end up with a crop top so small, you can’t breathe. 

If you’re making items that don’t have to fit, you may be able to get away with scaling up or down a few hook sizes. Items like these include: washcloths, dishcloths, scarves, pillows, and toys. 

Note that for stuffed items like toys or pillows, if you go up too many hook sizes, then you may end up with gaps in the fabric. This can cause stuffing to be seen or bulge out. 

Blankets are a bit of a special case. If you’re making a blanket that is intended to perfectly fit on top of a certain size of mattress, such as a King or Queen mattress, then you may not want to risk making it too small. But if the blanket is mostly going to be used for warmth and not presentation, then you may choose to use your favorite hook size and work until it’s long and wide enough to your liking. 

If the finished item has to fit something, and you need to switch hooks, then try to match the gauge that the pattern calls for.

Can You Match the Gauge?

Gauge is the number of stitches and number of rows that you make per square inch of fabric. It depends on your hook size, your tension, and the weight of your yarn. Some pattern authors specify a gauge in their patterns that you need to meet. 

The reason they do this is everyone crochets differently. Some people crochet more tightly or more loosely than the pattern author would. Pattern authors often tell you what their gauge was. 

That way, if you want to make a sweater that comes out the size that the pattern author intended, you need to match their gauge. You do so by making a swatch in the stitch that’s called for, then using a ruler to measure how many of your stitches fit in an inch horizontally, and how many rows fit in an inch vertically. 

If your gauge doesn’t match that of the author’s, you can switch to a different hook size or style, or you can adjust your tension and make another swatch until you match.

Measuring gauge of a swatch

This is a swatch of single crochet stitches. The gauge here is 8 stitches over 2 inches, and approximately 9 rows over 2 inches.

So that means my gauge is 8 stitches, and 9 rows over 2 inches in single crochet made with a G-6 (4 mm) hook and worsted weight yarn.

Are You in the Middle of That Project? 

Swapping hook sizes when you’re partway through a project can be risky and is generally not recommended. That being said, if you understand and accept the risks, you may want to give it a try. 

The main problem with changing hook size in the middle of a project is that the proportions of the project can be thrown off. Inconsistent proportions can make a project look sloppy. 

For example, if you’re making something rectangular like a blanket, and you switch to a smaller hook, the blanket can suddenly start looking more narrow partway through. 

This happened to a blanket of mine – you can see the blanket is wider around the yellow and white parts, but narrows when the yarn changes to teal.

Or, if you’re crocheting a sweater from the top down (from the collar to the waistline) and you switch to a larger hook halfway down the abdomen, then your sweater may widen and flare out, like a skirt. This may not be flattering. 

The change can happen in non-rectangular shapes, too, but it will likely be most obvious in a rectangle. 

If you do decide to change hook sizes, keep an eye on the project to make sure it won’t come out looking too wonky. 

Another issue with switching hook sizes midway is that some crochet projects are made up of equally sized, smaller pieces that are later sewn together. A few examples of these are granny squares and stuffed toys (also known as amigurumi.) The issue with changing hooks partway is that even a subtle change can yield pieces that are noticeably different in size.

For example, let’s say you’re making a blanket that requires 90 granny squares. If you already made 30 of them in one size, then if you make the other 60 slightly smaller or larger, you may not be able to fit them all together properly to wind up with a rectangular blanket. 

Or, if you’re making a stuffed teddy bear and you made one ear and one leg with one hook, then if you change hook sizes, the size difference between its ears and legs may be noticeable. Then the bear won’t come out looking symmetrical. 

If you are making only a small change to hook size, you may be able to get away with switching in the middle of a project, especially if your hook and yarn is on the larger side. 

If you’re working with smaller hooks and smaller yarns, though, the differences between hooks even less than a millimeter different from each other can lead to big consequences. And that brings us to the next factor to consider. 

The Difference Between Two Adjacent Hook Sizes Is Not Always Equal – The Smaller the Hook, The Bigger the Differences Between Hook Sizes

You may think that the difference between a US H and a US I hook would be the same as the difference between a US B and a US C hook. But that’s not the case!

Even though it seems like a minor change, the bigger the hook, the less difference going up or down a hook size is likely to make. But when you get to smaller hooks, the differences between hooks has a much bigger impact. 

To illustrate this difference, take a look at these two hearts made with crochet thread and tiny steel hooks. 

The larger heart is more than twice the size of the smaller heart. 

The larger heart was made with a US 12 (1.00 mm) hook, and the smaller heart was made with a US 14 (0.75 mm) hook. 

This is such a drastic difference even though there is only a 0.25 mm difference in the sizes of the hook. To put things in perspective, 0.25 mm is about as thick as 2 sheets of copy paper. 

On the other extreme, a 0.25 mm difference between two large hooks is not likely to yield such drastically different results in a project. In fact, in US sizing, we don’t even have numbers/letters for such small differences in hooks. 

A US Q hook is 16 mm. The next size up would be a US R hook, at 17 mm. 

Manufacturer Matters

In theory, hooks should be the same if they’re the same size. In reality, this isn’t the case. 

Sometimes even if two hooks are labeled as the same size, the stitches they’ll make will turn out to be different sizes because the design or shape of the hook is different. 

There are a variety of crochet hook manufacturers and they all make their hooks slightly differently. 

Differences can also result due to the style of hook – like whether it’s a tapered (sometimes called Boye) or inline (sometimes called Bates) hook. 

The green hook is a tapered hook, while the pink one is an inline hook.


Even the same manufacturer sometimes will have different models of hook – like a simple aluminum one, or a fancier ergonomic hook with a handle. 

These differences can cause you to hold a hook differently, and possibly work with it differently. 

For example, an ergonomic hook can feel much more comfortable, leading you to hold it with a much more relaxed grip, which will result in looser tension and bigger stitches. 

A cold, metal hook can cause you to grip the hook and your yarn much more tightly, causing you to make smaller stitches. 

Crochet hooks in different shapes and styles

Because of these differences, it’s a good idea to use the same hook throughout a project, unless the pattern specifically calls for a hook change. To keep track of the hook you used, you can use a crochet journal, or upload your notes about a project to Ravelry. 

I like to use Ravelry because then I can access it anywhere I have access to the internet. This means I can look up project notes on a phone if I’m crocheting on the go, or look it up from a friend’s or relative’s computer if I’m visiting. 

Still Not Sure What Hook to Use? 

If you are following a specific pattern, check Ravelry to see if others have uploaded project details for that pattern. You’ll be able to see this in the “projects” tab on a pattern’s page. 

People may have uploaded the hook size they used, along with pictures and any comments they had. You can look through these details of each project by clicking “more”. 

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