Number Sizes

Inside

Inside

Inside

Inside

Wheat Sheaf

US/Canada

Diameter

Diameter

Circumference

Circumference

British

French

Italy

German

Japanese

Swiss

Standard

(inches)

(mm)

(inches)

(mm)

Irish

Equivalent

Equivalent

Equivalent

Equivalent

Equivalent

Australian

Equivalent

0

0.458

11.6

1.438

36.5

12 5/8

1/4

0.466

11.8

1.463

37.2

1/2

0.474

12.0

1.488

37.8

A

3/4

0.482

12.2

1.513

38.4

A 1/2

1

0.490

12.4

1.539

39.1

B

1

1 1/4

0.498

12.6

1.564

39.7

B 1/2

1 1/2

0.506

12.9

1.589

40.4

C

1 3/4

0.514

13.1

1.614

41.0

C 1/2

2

0.522

13.3

1.639

41.6

D

2

1.50

2 1/4

0.530

13.5

1.664

42.3

D 1/2

2 1/2

0.538

13.7

1.689

42.9

E

3

2.75

2 3/4

0.546

13.9

1.714

43.5

E 1/2

3

0.554

14.1

1.740

44.2

F

44

4

14

4

4.00

3 1/4

0.562

14.3

1.765

44.8

F 1/2

45

5

14 1/4

5

5.25

3 1/2

0.570

14.5

1.790

45.5

G

45.75

5.5

14 1/2

3 3/4

0.578

14.7

1.815

46.2

G 1/2

46

6

14 7/8

6

6.50

4

0.586

14.9

1.840

46.8

H 1/2

47

6.75

15

7

4 1/4

0.594

15.1

1.865

47.4

I

47.75

7

15 1/8

7.75

4 1/2

0.602

15.3

1.890

48.0

I 1/2

48.25

8

15 1/4

8

4 3/4

0.610

15.5

1.915

48.7

J

49.25

9

15 5/8

9.00

5

0.618

15.7

1.941

49.3

J 1/2

50

9.5

15 3/4

9

5 1/4

0.626

15.9

1.966

49.9

K

50.5

10

15 7/8

10.00

5 1/2

0.634

16.1

1.991

50.6

L

51.75

10.5

16

10

5 3/4

0.642

16.3

2.016

51.2

L 1/2

52

11

16 3/8

11.75

6

0.650

16.5

2.041

51.8

M

52.75

11.5

16 1/2

11

12.75

6 1/4

0.658

16.7

2.066

52.5

M 1/2

53.25

12.25

16 3/4

12

6 1/2

0.666

16.9

2.091

53.1

N

54

13

17

13

14.00

6 3/4

0.674

17.1

2.116

53.8

N 1/2

54.5

13.75

17 1/8

7

0.682

17.3

2.141

54.3

O

55.25

14.5

17 1/4

14

15.25

7 1/4

0.690

17.5

2.167

55.0

O 1/2

56

15.25

17 1/2

7 1/2

0.698

17.7

2.192

55.6

P

56.5

16

17 3/4

15

16.50

7 3/4

0.706

17.9

2.217

56.3

P 1/2

57

16.5

17 5/8

8

0.714

18.1

2.242

56.9

Q

57.75

17

18

16

17.75

8 1/4

0.722

18.3

2.267

57.5

Q 1/2

58.25

17.75

17 1/4

8 1/2

0.730

18.5

2.292

58.2

R

58,75

18.5

18 1/2

17

8 3/4

0.738

18.7

2.317

58.9

R 1/2

59,25

19

18 3/4

19

9

0.746

18.9

2.342

59.5

S

60

19.5

19

18

9 1/4

0.754

19.2

2.368

60.1

S 1/2

60,5

20.25

19 1/4

20.25

9 1/2

0.762

19.4

2.393

61

S 3/4

61

21

19 1/2

19

9 3/4

0.770

19.6

2.418

61.6

T

61,75

21.5

19 3/4

21.5

10

0.778

19.8

2.443

62.3

T 1/2

62,25

22

20

20

10 1/4

0.786

20.0

2.468

62.7

U

62,75

22.75

21

10 1/2

0.794

20.2

2.493

63.5

U 1/2

63.5

23.5

20 1/4

22

22.75

10 3/4

0.802

20.4

2.518

64.0

V

64.25

24.25

20 1/2

11

0.810

20.6

2.543

64.8

V 1/2

64.75

25

20 3/4

23

11 1/4

0.818

20.8

2.569

65.3

W

65.5

25.75

21

25.25

11 1/2

0.826

21.0

2.594

65.9

W 3/4

66.25

26.5

21

24

11 3/4

0.834

21.2

2.619

66.5

X 1/4

66.75

27

21 1/4

12

0.842

21.4

2.644

67.2

Y

67.5

27.5

21 1/4

25

27.50

12 1/4

0.850

21.6

2.669

67.8

Y 1/2

68

28

21 1/2

12 1/2

0.858

21.8

2.694

68.4

Z

68.75

28.5

21 3/4

26

28.75

12 3/4

0.866

22.0

2.719

69.1

Z 1/2

69.25

29.25

21 3/4

13

0.874

22.2

2.744

69.7

70

30

22

27

13 1/4

0.882

22.4

2.769

70.3

Z1

70,75

31

13 1/2

0.890

22.6

2.795

71.0

71,5

32

13 3/4

0.898

22.8

2.820

71.6

Z2

72,25

33

14

0.906

23.0

2.845

72.3

Z3

73

34

14 1/4

0.914

23.2

2.870

72.9

35

14 1/2

0.922

23.4

2.895

73.5

Z4

74,25

14 3/4

0.930

23.6

2.920

74.2

75

15

0.938

23.8

2.945

74.8

Z5

75,5

15 1/4

0.946

24.0

2.970

75.4

15 1/2

0.954

24.2

2.996

76.1

15 3/4

0.962

24.4

3.021

76.7

16

0.970

24.6

3.046

77.4