Crochet Hook Size Chart
Crochet hooks are labelled three ways — millimetres, US letters and numbers, and old UK numbers — which makes patterns from different countries confusing. Pick any size to convert it, see which yarn weights suit it, and use the gauge helper: enter the stitches per 4 inches your pattern asks for and the number you got, and it tells you which hook to try next.
Crochet hook converter and gauge helper
Crochet Hook & Gauge Pack
Printable crochet hook size chart (mm, US, UK), a hook-to-yarn weight guide, a gauge swatch record sheet, a hook inventory (Excel) and a printable 4-inch gauge ruler.
- Hook chart (PDF/XLSX)
- Hook to yarn guide (PDF)
- Swatch record (XLSX)
- Hook inventory (XLSX)
- Gauge ruler (PDF)
Formats: PDF, XLSX. Instant download after payment (link valid 72 hours, up to 5 downloads). AI-assisted: the templates were drafted with AI help and reviewed and laid out by Kedop.
$3.00 USD, one-time
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Crochet hook size chart
| Millimetres | US | Old UK |
|---|---|---|
| 2.25 mm | B-1 | 13 |
| 2.75 mm | C-2 | 12 |
| 3.25 mm | D-3 | 10 |
| 3.5 mm | E-4 | 9 |
| 3.75 mm | F-5 | — |
| 4.0 mm | G-6 | 8 |
| 4.5 mm | 7 | 7 |
| 5.0 mm | H-8 | 6 |
| 5.5 mm | I-9 | 5 |
| 6.0 mm | J-10 | 4 |
| 6.5 mm | K-10½ | 3 |
| 8.0 mm | L-11 | 0 |
| 9.0 mm | M/N-13 | 00 |
| 10 mm | N/P-15 | 000 |
| 15 mm | P/Q | — |
| 16 mm | Q | — |
| 19 mm | S | — |
The millimetre size is the diameter of the hook’s shaft and is the most reliable label. US letters and numbers are standard for most brands but a few sizes vary slightly between makers; old UK numbers run in reverse (smaller numbers are bigger hooks).
Which hook for which yarn
| Yarn weight | Typical hook |
|---|---|
| 0 Lace / thread | Steel hooks 1.4–2.25 mm |
| 1 Super Fine (sock, fingering) | 2.25–3.5 mm (B-1 to E-4) |
| 2 Fine (sport, baby) | 3.5–4.5 mm (E-4 to 7) |
| 3 Light (DK) | 4.5–5.5 mm (7 to I-9) |
| 4 Medium (worsted, aran) | 5.5–6.5 mm (I-9 to K-10½) |
| 5 Bulky (chunky) | 6.5–9 mm (K-10½ to M/N-13) |
| 6 Super Bulky | 9–15 mm |
| 7 Jumbo | 15 mm and larger |
These follow the standard yarn weight guidelines; the yarn label usually suggests a hook too. Amigurumi (stuffed toys) typically uses a hook one or two sizes smaller than the label suggests for tight stitches that don’t show stuffing.
Steel hooks for thread crochet
Thread crochet — doilies, lace, fine edgings — uses small steel hooks sized from about 0.6 mm to 2.25 mm. Steel hook numbers run backwards: the higher the number, the smaller the hook. Because numbering differs between brands, check the millimetre size stamped on the hook when following a pattern, and match thread size (such as size 10 crochet cotton) to the pattern’s recommendation.
Getting gauge with the right hook
- Crochet a swatch at least 6 × 6 inches (15 × 15 cm) in the pattern stitch.
- Block it the way you will block the finished item.
- Count stitches and rows over 4 inches (10 cm) in the middle of the swatch.
- Too many stitches? Your stitches are small — use a bigger hook.
- Too few stitches? Your stitches are large — use a smaller hook.
- Repeat until your gauge matches.
The gauge helper above suggests the next hook to try. A difference of a stitch or two per 4 inches can change the size of a sweater by several inches.
Hook styles
| Style | Notes |
|---|---|
| Inline | Head and shaft the same width; deep throat; some find stitches more even |
| Tapered | Throat narrows; smooth stitch flow |
| Ergonomic | Cushioned or shaped handles to reduce hand strain |
| Tunisian | Long hooks, sometimes with cables, for Tunisian crochet |
| Materials | Aluminium (smooth, fast), bamboo/wood (grippy, warm), plastic (light, large sizes) |
Worked example
A pattern calls for a 5.5 mm (I-9) hook and 14 stitches per 4 inches. Your swatch with the 5.5 mm hook gives 16 stitches — tighter than the pattern. The helper suggests trying a larger hook, 6.0 mm (J-10), or 6.5 mm if the difference persists, and warns that at your current gauge the project would come out about 14% smaller than intended. A second swatch with the 6.0 mm hook matches.
Tension and grip
Hook size is only half of gauge — your tension matters too. Some crocheters naturally work tightly and always go up a size; others work loosely and go down. Tension can change with mood, fatigue or a new project, so check gauge again partway through large items like blankets and sweaters. An ergonomic hook or a different grip (pencil or knife hold) can make tension more even and reduce hand strain on long sessions.
Reading hook sizes in patterns
Patterns from the US usually give letter and millimetre sizes (“5.0 mm / H-8”). UK and European patterns give millimetres, and older UK patterns may use numbers. When a pattern lists only a letter, use the chart to find the millimetre size and check your hook’s shaft stamp — some brands’ G-6 is 4.0 mm and others 4.25 mm.
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Frequently asked questions
What size is an H crochet hook?
5.0 mm (H-8).
What hook for worsted yarn?
Usually 5.5–6.5 mm (I-9 to K-10½).
Why is my project too small?
Your gauge is too tight; try a larger hook.
Do UK hook numbers match US numbers?
No — old UK numbers run in reverse and differ; use millimetres.
What hook for amigurumi?
Often one or two sizes smaller than the yarn label suggests.
What does the letter on a crochet hook mean?
It is the US size designation; always check the millimetre size too.
Can I use a knitting needle size chart for hooks?
Millimetres match, but US letter and number systems differ between needles and hooks.
What hook is best for beginners?
A 5.0–5.5 mm (H-8 or I-9) hook with medium worsted yarn is easy to see and handle.
Do hook sizes affect how much yarn I use?
Yes, larger hooks make bigger, looser stitches that use more yarn per area.
Is my data stored?
No, it runs in your browser.