Confused by US and English terms here are some handy conversion charts for knitting needle and crochet hook sizes, and yarn comparisons.   

UK/US yarn conversion

UK

US

4ply

sport

double knitting

light worsted

aran

fisherman/worsted

chunky

bulky

super chunky

extra bulky

 

Knitting needle conversion chart

UK

Metric

US

14

2mm

0

13

2¼mm

1

-

2½mm

-

12

2¾mm

2

11

3mm

-

10

3¼mm

3

-

3½mm

4

9

3¾mm

5

8

4mm

6

7

4½mm

7

6

5mm

8

5

5½mm

9

4

6mm

10

3

6½mm

10½

2

7mm

-

1

7½mm

-

0

8mm

11

00

9mm

13

000

10mm

15

-

12mm

17

-

15mm

19

-

20mm

36

-

25mm

50

 

Crochet hook handy conversion Chart

UK

Metric

US

14

2

B/1

13

2.25

-

12

2.5

C/2

11

3

-

10

3.25

D/3

9

3.5

E/4

8

4

G/6

7

4.5

7

6

5

H/8

5

5.5

I/9

4

6

J/10

3

6.5

K/10½

2

7

-

0

8

-

-

9

-

9

10

-