What are the crochet hook sizes from mm to US?

Common crochet hook sizes: 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), 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 down to 0.75 mm.

Crochet Hooks

Q: What size crochet hook should I use?

Start with the hook size printed on your yarn label, then adjust to match your gauge. DK yarn pairs with a 4.0 mm (G/6) hook and worsted with a 5.0 to 5.5 mm (H/8 to I/9) hook.

Q: What is the best crochet hook for arthritis?

Ergonomic hooks with cushioned or contoured handles, such as the Addi Swing or Clover Amour, reduce hand strain during long crochet sessions.

Q: What is a Tunisian crochet hook?

A Tunisian or afghan crochet hook is a longer hook, often with a cable, that holds many loops at once for Tunisian crochet.

Shop crochet hooks for every project and every hand at Paradise Fibers, from smooth aluminum and warm bamboo to ergonomic comfort grips, fine steel thread hooks, Tunisian hooks, and complete sets. The right hook makes every stitch easier, whether you are working delicate lace, cozy blankets, or amigurumi.

New: not sure which hook to choose? Read our complete crochet hook buying guide for the full size chart, materials, and tips.

Crochet hook sizes (mm to US)

Crochet hooks are measured by shaft diameter in millimeters, with a US letter or number equivalent. Match the hook to your yarn weight, then size up or down to hit your gauge.

Metric (mm)	US size	Typical yarn
2.25 mm	B/1	Thread, fine cotton
2.75 mm	C/2	Sock, fingering
3.25 mm	D/3	Sport, amigurumi
3.5 mm	E/4	DK, amigurumi
3.75 mm	F/5	DK
4.0 mm	G/6	DK, light worsted
5.0 mm	H/8	Worsted
5.5 mm	I/9	Worsted, aran
6.0 mm	J/10	Aran
6.5 mm	K/10.5	Chunky
8.0 mm	L/11	Bulky
9.0 mm	M-N/13	Super bulky
10.0 mm	N-P/15	Super bulky

For thread crochet and lace, steel crochet hooks run finer, from roughly 1.75 mm down to 0.75 mm (US sizes 5 to 14). See the full breakdown in our crochet hook buying guide.

Types of crochet hooks

Aluminum: smooth, fast, and affordable in every size. Shop Boye aluminum hooks.
Ergonomic and comfort grip: cushioned, contoured handles that ease hand fatigue and arthritis. See the Addi Swing range.
Bamboo and wood: warm, lightweight, and grippy on slippery yarns. Try Brittany Birch and ChiaoGoo.
Steel and thread: fine hooks for lace, doilies, and thread crochet.
Tunisian (afghan) hooks: long or cabled hooks that hold many loops for Tunisian crochet. Shop Tunisian crochet hooks.
Sets: get every size at once with a crochet hook set.

Shop crochet hooks by brand

Boye · Clover · Addi · ChiaoGoo · Brittany Birch · HiyaHiya

Frequently asked questions

What size crochet hook should I use?
Start with the hook size on your yarn label, then adjust to match your gauge. As a guide, DK yarn pairs with a 4.0 mm (G/6) hook and worsted with a 5.0 to 5.5 mm (H/8 to I/9) hook.

What is the best crochet hook for arthritis?
Ergonomic hooks with cushioned or contoured handles, like the Addi Swing or Clover Amour, reduce hand strain during long sessions.

What hook should I use for amigurumi?
Use a hook one to two sizes smaller than the yarn recommends so stitches stay tight and the stuffing stays hidden. Pair it with the right amigurumi yarn.

What is a Tunisian crochet hook?
A longer hook, often with a cable, that holds many loops at once for Tunisian (afghan) crochet. Browse Tunisian hooks.