Guide to Sizing

WHAT NEEDLE OR HOOK DO I USE?

Knitting needles and crochet hooks can vary in the way they are labelled depending on whether you're using needles that are in metric size, US size or UK size.

The following table can be helpful if you need to convert knitting needle sizes:

Needle conversion chart

HOW ARE YARN WEIGHTS CATEGORISED?

The table below from the US Craft Council outlines some general yarn weight categories and suggests suitable needle and hook sizes in metric and US sizings.

Categories of yarn, gauge ranges, and recommended needle and hook sizes:

Yarn Weight Symbol 
& Category Names
lace super fine fine light medium bulky super bulky jumbo
Type of
Yarns in
Category
Fingering
10-count 
crochet 
thread
Sock, Fingering, Baby Sport,
Baby
DK,
Light
Worsted
Worsted,
Afghan,
Aran
Chunky,
Craft,
Rug
Super Bulky,
Roving
Jumbo,
Roving
Knit Gauge
Range* in
Stockinette
Stitch to 4 inches
33–40**
sts
27–32
sts
23–26
sts
21–24
sts
16–20
sts
12–15
sts
7–11
sts
6 sts and fewer
Recommended
Needle in
Metric Size
Range
1.5–2.25
mm
2.25—
3.25
mm
3.25—
3.75
mm
3.75—
4.5
mm
4.5—
5.5
mm
5.5—
8
mm
8—
12.75 mm
12.75 mm and larger
Recommended
Needle U.S.
Size Range
000–1 1 to 3 3 to 5 5 to 7 7 to 9 9 to 11 11
to 17
17
and
larger
Crochet Gauge*
Ranges in
Single Crochet
to 4 inch
32–42
double
crochets**
21–32
sts
16–20
sts
12–17
sts
11–14
sts
8–11
sts
7–9
sts
6 sts and fewer
Recommended
Hook in Metric
Size Range
Steel***
1.6–1.4
mm
Regular hook
2.25 mm
2.25—
3.5
mm
3.5—
4.5
mm
4.5—
5.5
mm
5.5—
6.5 
mm
6.5—
9
mm
9—
15 mm
15
mm and
larger
Recommended
Hook U.S.
Size Range
Steel***
6, 7, 8
Regular
hook B–1
B–1
to
E–4
E–4
to
7
7
to
I–9
I–9
to
K–10 1⁄2
K–10 1⁄2 to
M–13
M–13
to Q
Q
and
larger

* GUIDELINES ONLY: The above reflect the most commonly used gauges and needle or hook sizes for specific yarn categories.

** Lace weight yarns are usually knitted or crocheted on larger needles and hooks to create lacy, openwork patterns. Accordingly, a gauge range is difficult to determine. Always follow the gauge stated in your pattern.

*** Steel crochet hooks are sized differently from regular hooks—the higher the number, the smaller the hook, which is the reverse of regular hook sizing