Crochet Hook Sizes: The Complete Buying Guide
Crochet hooks are sized by the diameter of the shaft, in millimeters. US hooks also carry a letter and a number, and the UK had its own numbers before it went metric. This page has the full size chart, steel hook sizes for thread work, and notes on materials, head shapes, ergonomic and Tunisian hooks, and the brands we carry. Everything mentioned here is in our crochet hooks collection.
Crochet hook sizes chart (mm to US)
Go by the millimeter size. US letters aren't fully standard between brands: Addi labels its 4.0 mm hook F and its 4.5 mm hook G, while this chart and most US brands call those G/6 and 7. Find your yarn weight, start with the hook the ball band suggests, and change sizes until you match the gauge in your pattern.
| Metric (mm) | US size | UK/Canada | Typical yarn weight |
|---|---|---|---|
| 2.25 mm | B/1 | 13 | Lace, thread, fine cotton |
| 2.75 mm | C/2 | 12 | Sock, fingering (1) |
| 3.25 mm | D/3 | 10 | Sport (2), amigurumi |
| 3.5 mm | E/4 | 9 | DK (3), amigurumi |
| 3.75 mm | F/5 | - | DK (3) |
| 4.0 mm | G/6 | 8 | DK to light worsted (3-4) |
| 4.5 mm | 7 | 7 | Worsted (4) |
| 5.0 mm | H/8 | 6 | Worsted (4) |
| 5.5 mm | I/9 | 5 | Worsted to aran (4) |
| 6.0 mm | J/10 | 4 | Aran (4) |
| 6.5 mm | K/10.5 | 3 | Chunky (5) |
| 8.0 mm | L/11 | 0 | Bulky (5) |
| 9.0 mm | M-N/13 | 00 | Super bulky (6) |
| 10.0 mm | N-P/15 | 000 | Super bulky (6) |
| 15.0 mm | P-Q | - | Jumbo (7) |
| 16.0 mm | Q | - | Jumbo (7) |
Steel (thread) crochet hook sizes
Steel hooks are for crochet thread, doilies and fine lace. They have their own numbers, and the numbers run backwards: the higher the number, the smaller the hook. Brands don't agree on these either. Clover's steel 10 is 0.75 mm, while the US steel 10 below is 1.30 mm, so check the millimeters on the package.
| Metric (mm) | US steel size |
|---|---|
| 1.75 mm | 5 |
| 1.65 mm | 7 |
| 1.50 mm | 8 |
| 1.40 mm | 9 |
| 1.30 mm | 10 |
| 1.10 mm | 11 |
| 1.00 mm | 12 |
| 0.75 mm | 14 |
How to choose the right crochet hook size
- Start with the yarn label. Most ball bands give a recommended hook size, and that's your starting point.
- Crochet a swatch and measure it against the pattern's gauge. Too many stitches per inch means your stitches are too small, so go up a hook size. Too few, go down.
- Then adjust for the project. Amigurumi usually wants a hook a size or two smaller than the label so the fabric is tight and the stuffing doesn't show. Shawls and wraps often look better a size up, where the fabric drapes more.
Crochet hook materials
- Aluminum: smooth and quick, hard to break, and inexpensive. Most crocheters own a pile of these.
- Bamboo and wood: lighter and warmer in the hand, with a little grip that helps with slippery yarns like silk and bamboo.
- Steel: thin and stiff, for thread and lace.
- Plastic: light and cheap, and the usual material for jumbo hooks, where aluminum would get heavy.
- Ergonomic: a metal hook set into a thicker, cushioned handle. More on these below.
Ergonomic crochet hooks (for hand comfort and arthritis)
A plain aluminum hook is thin, so you end up pinching it, and over a long session that pinch is what makes hands and wrists ache. An ergonomic hook puts a thicker, softer handle around the metal so you can hold it with a looser grip. If you crochet for hours or have arthritis, it's worth trying one.
The Addi Swing has a curved handle shaped to sit in your palm, with a little flex to it, in sizes from 0.5 mm to 8 mm. The Swing Maxi is the same hook made a bit longer (6.7 inches instead of 6.3). Clover's Amour hooks have soft rubber handles, and we carry them in the steel sizes for thread work.
Inline vs tapered hook heads
Hook heads come in two main shapes:
- Tapered (Boye style): a rounded head and a gently sloped throat. It slides into stitches easily, and a lot of people find it faster.
- Inline (Bates style): the head is the same width as the shaft, with a deeper throat cut straight in. It holds the yarn more securely, and some people get more even stitches with it.
Neither one is better. It depends on how you hold the hook and how you make your stitches. If you keep splitting the yarn or losing loops, try the other shape.
Tunisian (afghan) crochet hooks
Tunisian crochet picks up a whole row of loops onto the hook and then works them back off, which is why the hooks are long and why the fabric looks a bit like knitting. A straight Tunisian hook with a stopper on the end is fine for scarves and dishcloths. For an afghan you need a hook with a cable attached, like the ChiaoGoo 24 inch Tunisian hook, or an interchangeable set where hook tips screw onto cables of different lengths. We keep them together under Tunisian crochet hooks.
Individual hooks vs sets
Buy a single hook when a pattern calls for a size you don't have. A crochet hook set makes more sense when you're starting out, switching to an ergonomic style, or tired of hunting for the right size. Sets usually cost less per hook and come in a case.
Crochet hooks by brand
- Boye: the classic American tapered aluminum hook, plus steel hooks, jumbo plastic hooks and the CrochetMaster set.
- Clover: Amour steel hooks with soft rubber handles, for thread and fine lace.
- Addi: made in Germany. The ergonomic Swing and the longer Swing Maxi.
- ChiaoGoo: bamboo hooks, plus T-Spin interchangeable and cabled Tunisian hooks.
- Brittany Birch: wooden hooks made in the USA from sustainably harvested birch.
- HiyaHiya: better known for knitting needles, but they also make a crochet hook gift set.
What hook do I need for amigurumi?
Amigurumi is crocheted tightly so the stuffing stays hidden, so use a hook one or two sizes smaller than the yarn label suggests. With DK cotton that usually means 3.25 mm (D/3) or 3.5 mm (E/4). Smooth cotton shows the stitches clearly, and our amigurumi yarn collection has the ones that work best for it.
Frequently asked questions
What are crochet hook sizes from mm to US?
The common ones are 2.25 mm (B/1), 2.75 mm (C/2), 3.25 mm (D/3), 3.5 mm (E/4), 3.75 mm (F/5), 4.0 mm (G/6), 4.5 mm (7), 5.0 mm (H/8), 5.5 mm (I/9), 6.0 mm (J/10), 6.5 mm (K/10.5), 8.0 mm (L/11), 9.0 mm (M-N/13) and 10.0 mm (N-P/15). Steel thread hooks run from about 1.75 mm (US 5) down to 0.75 mm (US 14). Letters vary a little between brands, so go by millimeters.
What is the most common crochet hook size?
5.0 mm (H/8). It's the hook most worsted weight yarns call for, and worsted is the weight most people crochet with.
What size crochet hook should a beginner use?
A 5.0 mm (H/8) or 6.0 mm (J/10) with a smooth, light-colored worsted yarn. Bigger stitches in a light color are easier to see and count while you're learning.
What hook size is best for amigurumi?
One or two sizes smaller than the yarn label recommends, often 3.25 mm (D/3) or 3.5 mm (E/4) with DK cotton, so the stitches stay tight and the stuffing stays hidden.
Are crochet hook sizes the same as knitting needle sizes?
For regular hooks, mostly yes. On the Craft Yarn Council charts a G/6 hook and a US 6 needle are both 4.0 mm, and an H/8 hook and a US 8 needle are both 5.0 mm. Steel hooks are the exception, since their numbers run the other way. Not every brand sticks to the standard, so check the millimeters. Our yarn weight chart matches each yarn weight to both.