Inside ring circumference

Inside ring circumference

Inside ring circumference

(inches)            (inches)

(millimeter)

Standard for US & Canada

2.242                 2 1/4

56.9

8

2.267

57.6

8 1/4

2.292                2 5/16

58.2

8 1/2

2.317

58.9

8 3/4

2.342                2 11/32

59.5

9

2.368

60.1

9 1/4

2.393                  2 3/8

60.8

9 1/2

2.418

61.4

9 3/4

2.443                  2 7/16

62.1

10

2.468

62.7

10 1/4

2.493                   2 1/2

63.3

10 1/2

2.518

64.0

10 3/4

2.543                   2 9/16

64.6

11

2.569

65.2

11 1/4

2.594                   2 5/8

65.9

11 1/2

2.619

66.5

11 3/4

2.644                  2 21/32

 67.2

12

2.669

67.8

12 1/4

2.694                   2 11/16

68.4

12 1/2

2.719

69.1

12 3/4

2.744                   2 3/4

 69.7

13

2.769

70.3

13 1/4

2.795               2 13/16

71.0  

13 1/2

2.820

71.6

13 3/4

2.845                 2 7/8

 72.3

14

2.870

72.9

14 1/4

2.895                 2 29/32

73.5  

14 1/2

2.920

74.2

14 3/4

2.945                 2 15/16

74.8

15

2.970

75.4

15 1/4

2.996                      3

76.1

15 1/2

3.021

76.7

15 3/4

3.046                   3 1/16

77.4

16