Crochet Hook Size Charts from the US, UK, and Japan

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Crochet designer Lee Sartori explains how crochet hooks are sized

Co-authored by Lee Sartori and Elaine Heredia, BA

Last Updated: August 26, 2026 Fact Checked

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• Crochet Hook Size Charts
|
• Regular vs Steel Crochet Hooks
|
• Best Projects by Hook Size
|
• Choosing a Hook Size
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• Using the Wrong Hook Size
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• Video

|Show more |Show less

Crochet hook size has a big impact on the outcome of your project. But it can be confusing to find the right size, especially when different countries have different sizing conventions! Not to worry, though—we're here to untangle it for you. Keep reading to learn about crochet hook sizes from different countries, regular vs steel crochet hook sizes, and the best projects for different hook sizes, with insights from one of wikiHow’s crochet experts. We'll also explain how to choose the right hook size, and more!

Crochet Hook Size Chart (At a Glance)

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Crochet designer Lee Sartori says crochet hooks are sized in millimeters, though the name of the size differs between countries. This chart shows the standard (non-steel) hook sizes in millimeters and the corresponding U.S., UK, and Japan sizes. In the US, sizes increase as the letter gets further into the alphabet.

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Section 1 of 5:

Crochet Hook Sizing Chart (By Country)

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1. 
   1
   United States Crochet Hook ChartRegular U.S. crochet hook sizes use letters and numbers or millimeters (mm), explains Sartori. The smallest hook is B-1 (2.25 mm), and the largest hooks extend to the T/X (30 mm) range. Crochet hooks are also sized according to the shaft diameter in millimeters (mm), which is more accurate. This metric system also makes it easier to convert US sizes to sizes in other countries, like the United Kingdom and Japan. Here's a breakdown of the US letter/number sizes and their metric equivalents:

   • B-1 (2.25 mm)
   • D-3 (3.25 mm)
   • E-4 (3.50 mm)
   • F-5 (3.75 mm)
   • G-6 (4.00 mm), says Sartori
   • H-8 (5.00 mm), says Sartori
   • I-9 (5.50 mm)
   • J-10 (6.00 mm)
   • K-10 ½ (6.50 mm)
   • L-11 (8.00 mm)
   • M/N-13 (9.00 mm)
   • N/P-15 (10.00 mm)
   • P/Q (15.00 mm)
   • Q (15.75 mm)
   • Q (16.00 mm)
   • S (19.00 mm)
   • T/U/X (25.00 mm)
   • T/X (30 mm)
   • Note: Steel crochet hooks use a different sizing convention, which you can learn about under ”Regular vs Steel Crochet Hook Sizes” below!
   • Sartori adds that U.S. sizes are typically used in Canada, too.

   Meet the wikiHow Expert

   Lee Sartori is a crochet designer and expert who goes by Coco Crochet Lee online. She’s authored 14 crochet books and partnered with big names like Disney, Minecraft, and Pokémon.
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   United States Steel Crochet Hook Chart There are 2 main types of hooks in the U.S.: regular hooks made of plastic, wood, or aluminum, and steel crochet hooks. The steel hooks are best for working up fine, intricate details, like lace and small flowers. They're sized in numbers in ascending order. This means the bigger the number, the smaller the hook. Here's a chart showing the most common steel hook sizes, as well as their corresponding metric measurements:

   • 00 (3.50 mm)
   • 0 (3.25 mm)
   • 1 (2.75 mm)
   • 00 (2.70 mm)
   • 0 (2.55 mm)
   • 1 (2.35 mm)
   • 2 (2.25 mm-2.20 mm)
   • 3 (2.10 mm)
   • 4 (2.00 mm)
   • 5 (1.90 mm)
   • 6 (1.80 mm)
   • 4/0 (1.75 mm)
   • 5 (1.70 mm)
   • 7 (1.65 mm)
   • 6 (1.60 mm)
   • 8/7/2 (1.50 mm)
   • 9/8 (1.40 mm)
   • 10 (1.30 mm)
   • 9/4 (1.25 mm)
   • 10 (1.15 mm)
   • 11 (1.10 mm-1.05 mm)
   • 12/6 (1.00 mm)
   • 13 (0.95 mm)
   • 14/8 (0.90 mm)
   • 13 (0.85 mm)
   • 14/10 (0.75 mm)
   • 12 (0.60 mm)
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   United Kingdom Crochet Hook Chart Modern UK crochet hook sizes use millimeters, but the old versions use numbers. If you look at old crochet patterns from the UK, you might notice that they suggest hook sizes with decreasing numbers. That's the old sizing system. Modern hook sizes rely on the metric system. Below is a list of UK crochet hook sizes and their metric measurements:

   • 14 (2 mm)
   • 13 (2.25 mm)
   • 12 (2.50 mm)
   • 11 (2.75 mm)
   • 11 (3.00 mm)
   • 10 (3.25 mm)
   • 9 (3.50 mm)
   • 8 (3.75 mm)
   • 8 (4.00 mm)
   • 7 (4.50 mm)
   • 6 (5.00 mm)
   • 5 (5.50 mm)
   • 4 (6.00 mm)
   • 2 (7.00 mm)
   • 0 (8.00 mm)
   • 00 (9 mm)
   • 000 (10 mm)
   • Note: Sometimes, you might see UK crochet hook sizing charts with descending numbers labeled as "old." This is a reference to the fact that this sizing convention is no longer used. But it's still helpful to know in case you ever come across an old crochet pattern!
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   Japanese Crochet Hook Chart Japan crochet hook sizes use ascending numbers for bigger sizes. In Japan, the smallest crochet hook size is 2 (2 mm), and the numbers get bigger with the hook size. The biggest one is a 20-jumbo (19.00 mm).

   • 2/0 (2.00 mm)
   • 3/0 (2.25 mm)
   • 4/0 (2.50 mm)
   • 5/0 (3.00 mm)
   • 6/0 (3.50 mm)
   • 7/0 (4.00 mm)
   • 7.5/0 (4.50 mm)
   • 8/0 (5.00 mm)
   • 9/0 (5.50 mm)
   • 10/0 (6 mm)
   • 7-jumbo (7 mm)
   • 8-jumbo (8 mm)
   • 9-jumbo (9 mm)
   • 10-jumbo (10 mm)
   • 12-jumbo (12 mm)
   • 15-jumbo (15 mm)
   • 20-jumbo (19 mm)
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Section 2 of 5:

Regular vs Steel Crochet Hook Sizes

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1. 
   Regular hooks are sized in letters, and steel hooks are sized in numbers. In the U.S., when you read the size of a standard plastic, wooden, or aluminum crochet hook, you'll notice that the lower the letter is in the alphabet, the bigger the hook. These hooks are designed for regular-sized or large projects, not small details. Steel crochet hooks are designed for fine, delicate work, so they're smaller than regular hooks. They also use the opposite sizing convention: the bigger the number, the smaller the hook.

   • For example, a regular N-13 (9.00 mm) crochet hook is significantly larger than a B-1 (2.25 mm) hook.
   • Meanwhile, a size 12 (0.60 mm) steel hook is smaller than a size 00 (3.50 mm).
   • Sartori notes that all crochet hooks are sized in millimeters.

Section 3 of 5:

Best Projects for Different Crochet Hook Sizes

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1. 
   Use small hooks for delicate items and large hooks for big, cozy projects. Technically, you can use any size hook for any size project, but you may not get the result you're looking for. For example, if you want to crochet a scarf, you likely want tight stitches in a soft, low-weight yarn. To get those tight stitches, you need at least an F-5 hook. Here's a breakdown of the different U.S. crochet hook sizes and the types of projects you'll typically work up with each:

   • B-1 (2.25 mm) and C-2 (2.75 mm): Delicate details (i.e., lace or flowers)
   • D-3 (3.25 mm): Socks
   • E-4 (3.50 mm): Small baby items (i.e., booties and caps) and adult-sized accessories (i.e., cowls)
   • F-5 (3.75 mm): Cold weather accessories (i.e., cowls and shawls) and small afghans
   • G-6 (4.00 mm): Lightweight hats and scarves
   • H-8 (5.00 mm): Lightweight shawls, cardigans, and shirts
   • I-9 (5.50 mm): Baby blankets
   • J-10 (6.00 mm): Afghans and hats
   • K-10 ½ (6.50 mm): Wraps and basket covers
   • L-11 (8.00 mm): Bulky cowls and scarves
   • M: Cozy and warm hats, scarves, and cowls
   • N-13 (9.00 mm): Plush hats, scarves, and afghans
   • P-15 (10.00 mm) and up: Heavy items (i.e., afghans and rugs)
   • According to Sartori, the standard size range is from 4 millimeters to about 6 millimeters.
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Section 4 of 5:

How to Choose the Right Hook Size

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1. 
   1
   Follow the hook size recommended in the crochet pattern. If you're working with a crochet pattern, the designer will probably list the hook size you need, says Sartori. It's a good idea to use the hook size suggested in the pattern! That way, your project will turn out as close to the desired outcome as possible.
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   Use the hook size shown on your yarn label. If your pattern doesn't come with a hook size suggestion (or if you're inventing your own crochet pattern), check the label on your yarn skein. The label will specify the exact size range you should look for. This is important because yarn comes in different weights or thicknesses. In most cases, a bigger crochet hook is easier to work with for thick yarn, and a smaller hook is better for thinner, finer yarn.
3. 
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   Crochet a gauge swatch to test different hook sizes. Anytime you embark on a new crochet project (with or without a pattern), stitch a gauge swatch first. Gauge is a measurement of the number of stitches in a 4 in (10 cm) square piece of crochet work. Crochet swatches using different hooks and compare them. Count the number of stitches in the swatch, and note the texture, stitch size, and how well it stretches. Select the one that matches the gauge recommended in the pattern, and use that hook to crochet the final project.

   • Note: Most patterns specify a gauge to aim for, as well as the hook size and yarn weight to use.
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Section 5 of 5:

What happens when you use the wrong hook size?

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1. 1
   Your stitches may come out the wrong size. Bigger hooks make bigger stitches. So if you're doing a project that requires small, delicate stitchwork, using a big hook will make it come out wrong. On the other hand, if you use a small hook for a project that calls for big stitches, your plush, cozy item could come out tight and restrictive.
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   Your project may turn out bigger or smaller than expected. If you use a different size from the one your crochet pattern recommends, the project may not look the way you anticipated! For example, a large hook might make a small item, like a sock, too big for your foot. Meanwhile, a small hook could result in a large item, like an afghan, coming out way too small.
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