Crochet Hook Sizes & Types - Conversion Charts

One of the essential tools to create anything with crochet is, of course, your crochet hook. Understanding crochet hook sizes is an important skill to obtain. This can be a little confusing because different countries have different names for each size of hook. You will need to know where your crochet pattern originated in order to know which size hook is required.

Crotchet Hook Sizes

The diameter of the hook determines the crochet hook sizes.

• UK/Australia - If your hook size is in mm, they can range from 2mm to 35 mm. If you are using a UK or Canadian hook, or a really vintage hook from Gran’s old work-basket, these are also labeled with numbers, but not the same numbers as the mm size numbers!
• US - If you are using a USA hook, they are labeled with letters and numbers.

Crochet Hook Sizes Conversion Chart

To help make this easier, here is a table, showing various sizes of hooks and their equivalents.

Metric (mm)	US Sizes	UK Sizes
2		14
2.25	B-1
2.5
2.75	C-2	12
3		11
3.25	D-3	10
3.5	E-4
3.75	F-5	9
4	G-6	8
4.25
4.5	7	7
5	H-8	6
5.5	I-9	5
6	J-10	4
6.5	K-10.5	3
7		2
7.5
8	L-11	O
9	M/N-13	OO
10	N/P-15	OOO
12	O
15	P/Q
16	Q
19	S
25	U
35	Y

Steel Crochet Hook Sizes

Just to complicate things even further, the very fine crochet hooks, also known as steel hooks or lace hooks have their own system of sizing.

Metric (mm)	US sizes
0.6	12
0.75	14/10
0.85	13
0.9	14/8
0.95	13
1	12/6
1.05	11
1.1	11
1.15	10
1.25	9/4
1.3	10
1.4	9/8
1.5	8/7/2
1.6	6
1.7	5
1.8	6
1.9	5
2	4
2.1	3
2.2	2
2.25	2
2.35	1
2.55	0
2.7	0

How Do you Know What Crochet Hook Sizes to Choose?

The hook you choose will determine the size of your stitches.

• Smaller hooks create tighter finished items and a more solid fabric- because the gaps between the loops will be smaller.
• Larger hooks will create a loose weave type fabric with larger holes between the stitches.

The type of yarn you select will also affect the fabric you create.

Guidelines for the suitable crochet hook size for a particular yarn are usually printed on the yarn band which is wrapped around your yarn ball or skein. These are meant as guidelines only. For example, if you want a very loose, lacy look, you can use a large crochet hook with a thin, lightweight yarn or cotton. In the photo below, the label recommends 4 mm-sized hooks.

Crochet Hook sizes vs Gauge

When you are following a crochet pattern, there will almost always be a section on ‘Gauge’.

What is Crochet Guage?

Guage refers to the number of stitches and rows per inch on your crochet work. It is usually given as a measurement per 4” (10 cm) square. It is a measure of how big your stitches are. Everyone crochets differently. Some people make larger, looser loops and some make smaller, tighter loops.

So even if you are using the same size crochet hook and yarn as your best friend, your garment could end up way smaller or larger than theirs!

For this reason, when following a pattern, it is very important to check your gauge before starting on the actual garment. A LOT of people see this as an unnecessary delay, which prevents them from starting the interesting process of making the actual garment. I have to confess, that I was one of these people when I first started crocheting, but I learned my lesson the hard way!!

It really is worthwhile taking the time to do this, as you want your work to be the correct size, and you want to have the correct amount of yarn for your project. If you crochet fewer stitches per inch than the gauge of the pattern you may run out of yarn, and your garment will be too big. If you crochet more stitches per inch, you will have leftover yarn and your garment will be too small.

Your final project will also look and feel different from the original pattern if your gauge is incorrect.

How To Measure Gauge

To measure the gauge you will need to crochet a ‘swatch’. This is a small square of crochet fabric, made using the stitch you will be using for your garment or accessory.

Using the hook size and yarn thickness suggested in the pattern, Chain a number of stitches that will give you a width longer than 4” (10cm). Work up your swatch, using the stitches needed for your pattern until you have made a nice square of crochet, which must also be longer than the 4” (10cm).

Now measure the stitches and rows of your swatch. Place your ruler or tape measure horizontally along the stitches, preferably in a central position. Count how many stitches are within your 4” (10cm). Then place the tape measure vertically along your swatch and count how many rows fit into the 4” (10cm) measurement.

If you have managed to crochet to gauge, you can now continue to your main project.

How To Correct Gauge with Crochet Hook Sizes

• If you have more stitches than needed per 4”(10cm), your finished item will be too small. You should try using a larger crochet hook.
• If you have fewer stitches than needed, your crochet is too loose and your item will be too large. You must change to a smaller crochet hook.

If changing the size of your hook still doesn’t work, try using a crochet hook made from a different material. For example, you may find that you get a different tension with a plastic hook rather than with an aluminium one.

Types Of Crochet Hooks

Aside from their different sizes, the hooks can be made of different materials.

Plastic

Hooks are the most economical and are very lightweight. They have a very slight texture to them, so your stitches won't slip too easily. They are also perfect for airplane trips!

Metal

Hooks are most often made of aluminum for the larger hooks and steel for the very fine hooks. They are very smooth and slippery and the yarn glides easily when using them.

Wooden

Crochet hooks can be expensive, but are smooth and have a little bit of texture to stop the yarn from slipping. Collectors can order hand-made, bespoke wooden hooks with beautifully carved handles.

Bamboo

Hooks are very similar to wooden hooks, but lighter, and less expensive.

Ivory or Bone Crochet Hooks

Are hand carved and are usually antiques. You can specially order them to be custom made if this is what you like to work with.

Ergonomic Hooks

Have a shaft usually made of metal, which is the correct measurement for the size of hook,  and then a thicker base or handle. The handles can be made of plastic, rubber or wood. If you have arthritis, carpal tunnel syndrome, or any hand or wrist condition which makes it uncomfortable or painful to hold a thin hook, these will be the best type for you. Even if you have no problems, some people just prefer the feel of these hooks.

Tunisian Crochet Hooks

Are very long and thick. They are also called Afghan hooks. Tunisian crochet is different to normal crochet in that it is almost like a mixture between knitting and crochet. You have many more stitches on the hook than with conventional crochet, hence the need for an extra long hook.

Broomstick Lace Crochet Hooks

Are exceptionally thick (just like a broomstick!)and they are used to create large loops or eyelets in your crochet work, which gives a lacy effect.

How To Hold Your Crochet Hook

There is no hard and fast rule about how to hold your hook. You should hold it in any way that is comfortable for you, and that allows you to easily create the loops which form your stitches. There are two common ways of holding the hook:

Pencil Grip

You hold the hook in your dominant hand just as you would hold a pencil to write. The hook part should be facing you, and you grip the shaft between thumb and forefinger, with the other fingers supporting it underneath.

Knife Grip

You hold the hook in your dominant hand with your thumb and middle finger gripping the shaft while your forefinger rests along the top, as if holding a knife.

More important then the way you hold the hook, is the way you hold the yarn. You must keep the yarn at a constant tension all the time. It must be steady and tight.

Wrap the yarn around the little finger of your non-dominant hand, then raise your middle finger and lift the yarn with it to keep the tension fairly tight. Use your index finger and thumb to hold the work. Some crocheters prefer to use their forefinger as the tension holder.

Crochet Hook Sizes - In Conclusion

Now that you are fully conversant with the ‘tools of the trade’ and crochet hook sizes, you can start working on that fabulous sweater or afghan you have been wanting to make!