What Size Crochet Hook for Each Yarn Weight (Lace to Super Bulky)

Every crochet hook chart on the internet gives you the same grid of letters and millimetres, and every one of them stops exactly where the useful part starts — which hook to reach for when you are holding this ball of yarn, and what happens to the fabric when you deliberately break the rule. This is the version we wrote after pulling hooks off the wall at Yarn.com and crocheting the same swatch six times.

Two things worth knowing before the tables. First, the number on the yarn label is a knitting gauge recommendation far more often than a crochet one, so the hook it implies is usually a size small for crochet. Second, crochet uses more yarn per square inch than knitting at the same gauge — if you size up a hook to save yarn, size up your yardage estimate too, because it rarely works out the way people expect.

Crochet hook sizes: US letters, metric and steel

US hooks are labelled by letter and number, UK/Canadian hooks run the opposite direction (bigger number = smaller hook), and thread hooks are a separate steel scale entirely. The millimetre is the only measurement that never lies — when a pattern and a hook label disagree, believe the millimetres.

Sizes between 3.5 and 4 mm are where labelling gets messy: some brands call 3.5 mm E and others F, and 4.5 mm is a bare number (7) with no letter at all. If a pattern says "F hook", check the millimetres it also lists.

What size hook for each yarn weight — and what changes if you go up or down

Lace and fingering (weights 0–1): 1.5–3.5 mm

For shawls in fingering weight yarn, most crocheters are happier a full size above the label — 3.25 mm rather than 2.75 mm. Crochet stitches are already denser than knitted ones, and a lace shawl worked at knitting gauge comes out stiff as card. The tell is when you block it: if the fabric refuses to open up and stays exactly the size it was off the hook, the hook was too small. Go down to 2.25 mm only for edgings, colourwork tapestry crochet, and anything you want to hold a hard edge.

Sport and DK (weights 2–3): 3.5–5 mm

This is the range where the "crochet hook for DK weight yarn" question gets its most misleading answer. Labels on DK weight yarn almost always print a 4 mm knitting needle, so people reach for a 4 mm (G/6) hook, and for granny squares and garments that is genuinely right. For a DK blanket, size up to 4.5 or 5 mm: the drape difference between a G and an H hook across a whole afghan is the difference between a throw someone actually pulls over their legs and one that stands up on its own. Sport weight yarn sits at 3.5–4 mm, and it is the weight that most rewards a swatch, because sport and DK overlap so much in practice.

Worsted and Aran (weight 4): 5–6 mm

H/8 (5 mm) with worsted weight yarn is the most forgiving combination in crochet, and it is what we hand every beginner: the stitches are big enough to see, the fabric is firm enough that mistakes are visible before you have done six rows on top of them, and almost every free pattern is written for it. Move to I/9 (5.5 mm) if your stitches feel tight and your hand aches after twenty minutes — tension pain is usually a hook-size problem, not a technique problem.

Bulky and super bulky (weights 5–6): 6.5–10 mm

With bulky and super bulky yarn, the hook stops being about gauge and starts being about hand strain. A 9 mm hook in an unforgiving material will bruise the pad of your index finger over a long blanket session — this is the one range where we push people toward a cushioned grip regardless of what they usually crochet with. Also expect the fabric to grow after a few days of use: super bulky crochet relaxes more than any other weight, so make the piece slightly smaller than the target size, not slightly larger.

Amigurumi: go down, deliberately

For amigurumi you want fabric with no gaps for the stuffing to peek through, so drop 1–1.5 mm below the label: 2.75–3.25 mm with cotton yarn that a label would put on a 4 mm hook. It works your hands harder, which is why a smooth-shanked metal hook beats a grippy wooden one here — the yarn has to slide, because you are fighting the fabric on every stitch. If you can see white stuffing through your single crochet, that is your answer, no swatch required.

The swatch, done in under fifteen minutes

Skipping it is the reason most crocheted garments end up two sizes off. Chain about 20, work 5–6 rows in the pattern's main stitch, then measure across the middle rows and ignore the first and last — edge stitches always lie. If you have more stitches per 4 in than the pattern asks for, your stitches are too small: go up a hook. Fewer stitches, go down. One hook size moves crochet gauge by roughly half a stitch per inch, which over a 40 in blanket is about 4 in of width — a real difference, not a rounding error.

Two things people miss. Wash and dry the swatch the way the finished thing will be washed; superwash wool and cotton both relax dramatically the first time, and gauge measured dry off the hook is often a size out. And measure row height too, not just stitches — in crochet, row height is where a hook change shows up first, and a "correct" stitch count with the wrong row gauge is how sleeves end up short.

Which hook, not just which size

Once the millimetres are settled, material decides how the session feels. Aluminium is fast and slick, best for cotton and anything sticky. Wood grips wool, slows you down and is kindest to grabby single crochet. Cushioned grips solve pain, not gauge — they do not change your stitches, they change how long you can keep making them.

• KnitPro Wave 2.0 Deluxe — the shaped-handle option, and the one we recommend first for anyone whose hand cramps.
• KnitPro Aluminum Soft-Grip Silver — slick aluminium head with a soft barrel; the amigurumi-and-cotton pick.
• Lykke Driftwood 6" — warm wood with just enough grip for slippery wool singles.
• Clover Soft Touch — the long-session classic, sized right through the worsted range.

Browse the full range in crochet hooks, and if you are still choosing between materials and brands, our crochet hook buying guide goes deeper on that side of the decision.

Pick your hook in three questions

1. What weight is the yarn? Start at the middle of its range in the table above — not at the needle size on the label.
2. What is the fabric for? Drape (blanket, shawl, cardigan) → go up half a size. Structure (basket, bag, amigurumi, toy) → go down one or two.
3. Does the swatch match? Too many stitches per inch, go up a hook; too few, go down. Re-measure after washing.

If you are pairing yarn to a project from the other direction — picking the weight first — start from yarn by weight, and for crochet-specific yarn choices, crochet yarn and our crochet blanket patterns are the two places most projects begin.

FAQ

What size crochet hook should a beginner use?

A 5 mm (H/8) hook with a smooth, light-coloured worsted weight yarn. Stitches are large enough to read, most beginner patterns assume that pairing, and light yarn makes it easy to see where the hook goes.

What hook do I use for DK weight yarn?

4 mm (G/6) for garments and granny squares, 4.5–5 mm if you want a blanket with drape. Labels on DK almost always print a knitting needle size, which lands a bit small for crochet.

What size hook for chunky or super bulky yarn?

6.5–9 mm for bulky, 9 mm and up for super bulky. Prioritise a comfortable grip in this range — large hooks are where hand fatigue actually happens.

Is a US H hook the same as a 5 mm hook?

Yes. US H/8 is 5 mm. Letters vary between brands at some sizes, so the millimetre marking is always the one to trust.

Can I use a different hook size than the pattern says?

Yes, as long as your swatch matches the pattern's gauge. Hook size is a means to gauge, not a rule — that is why patterns say "or size needed to obtain gauge".

Why is my crochet fabric stiff?

Almost always a hook one or two sizes too small for the yarn. Go up a size and re-swatch before changing your tension, which is much harder to alter deliberately.