| Inside Diameter | Inside Circumference | Sizes | |||||
|---|---|---|---|---|---|---|---|
| inch | mm | inch | mm | United States & Canada | U.K., Ireland, Australia, & New Zealand | India, China & Japan | Switzerland |
| 0.459 | 11.63 | 1.44 | 36.5 | 0 | |||
| 0.466 | 11.84 | 1.46 | 37.2 | 1/4 | |||
| 0.474 | 12.04 | 1.49 | 37.8 | 1/2 | |||
| 0.482 | 12.24 | 1.51 | 38.5 | 3/4 | |||
| 0.49 | 12.45 | 1.54 | 39.1 | 1 | A | ||
| 0.498 | 12.65 | 1.56 | 39.7 | 1 1/4 | A 1/2 | ||
| 0.506 | 12.85 | 1.59 | 40.4 | 1 1/2 | B | ||
| 0.514 | 13.06 | 1.61 | 41.0 | 1 3/4 | B 1/2 | ||
| 0.522 | 13.26 | 1.64 | 41.7 | 2 | C | 1 | |
| 0.53 | 13.46 | 1.67 | 42.3 | 2 1/4 | C 1/2 | ||
| 0.538 | 13.67 | 1.69 | 42.9 | 2 1/2 | D | ||
| 0.546 | 13.87 | 1.72 | 43.6 | 2 3/4 | D 1/2 | 1.5 | |
| 0.554 | 14.07 | 1.74 | 44.2 | 3 | E | 2 | |
| 0.562 | 14.27 | 1.77 | 44.8 | 3 1/4 | E 1/2 | 2.75 | |
| 0.57 | 14.48 | 1.79 | 45.5 | 3 1/2 | F | 3 | |
| 0.578 | 14.68 | 1.82 | 46.1 | 3 3/4 | F 1/2 | 4 | |
| 0.586 | 14.88 | 1.84 | 46.8 | 4 | G | 4 | 5.25 |
| 0.594 | 15.09 | 1.87 | 47.4 | 4 1/4 | G 1/2 | 5 | |
| 0.602 | 15.29 | 1.89 | 48.0 | 4 1/2 | H | 6.5 | |
| 0.61 | 15.49 | 1.92 | 48.7 | 4 3/4 | H 1/2 | 6 | |
| 0.618 | 15.70 | 1.94 | 49.3 | 5 | I | 7 | 7.75 |
| 0.626 | 15.90 | 1.97 | 50.0 | 5 1/4 | J | ||
| 0.634 | 16.10 | 1.99 | 50.6 | 5 1/2 | J 1/2 | 8 | 9 |
| 0.642 | 16.31 | 2.02 | 51.2 | 5 3/4 | K | ||
| 0.65 | 16.51 | 2.04 | 51.9 | 6 | K 1/2 | 9 | 10 |
| 0.658 | 16.71 | 2.07 | 52.5 | 6 1/4 | L | ||
| 0.666 | 16.92 | 2.09 | 53.1 | 6 1/2 | L 1/2 | 10 | 11.75 |
| 0.674 | 17.12 | 2.12 | 53.8 | 6 3/4 | M | 12.75 | |
| 0.682 | 17.32 | 2.14 | 54.4 | 7 | M 1/2 | 11 | |
| 0.69 | 17.53 | 2.17 | 55.1 | 7 1/4 | N | 12 | 14 |
| 0.698 | 17.73 | 2.19 | 55.7 | 7 1/2 | N 1/2 | 13 | |
| 0.706 | 17.93 | 2.22 | 56.3 | 7 3/4 | O | 15.25 | |
| 0.714 | 18.14 | 2.24 | 57.0 | 8 | O 1/2 | 14 | |
| 0.722 | 18.34 | 2.26 | 57.6 | 8 1/4 | P | 16.5 | |
| 0.73 | 18.54 | 2.29 | 58.3 | 8 1/2 | P 1/2 | 15 | |
| 0.738 | 18.75 | 2.32 | 58.9 | 8 3/4 | Q | 17.75 | |
| 0.746 | 18.95 | 2.34 | 59.5 | 9 | Q 1/2 | 16 | |
| 0.754 | 19.15 | 2.37 | 60.2 | 9 1/4 | R | ||
| 0.762 | 19.35 | 2.39 | 60.8 | 9 1/2 | R 1/2 | 17 | 19 |
| 0.77 | 19.56 | 2.42 | 61.4 | 9 3/4 | S | ||
| 0.778 | 19.76 | 2.44 | 62.1 | 10 | S 1/2 | 18 | 20.25 |
| 0.786 | 19.96 | 2.47 | 62.7 | 10 1/4 | T | ||
| 0.794 | 20.17 | 2.49 | 63.4 | 10 1/2 | T 1/2 | 19 | 21.5 |
| 0.802 | 20.37 | 2.52 | 64.0 | 10 3/4 | U | ||
| 0.81 | 20.57 | 2.54 | 64.6 | 11 | U 1/2 | 20 | |
| 0.818 | 20.87 | 2.59 | 65.3 | 11 1/4 | V | 21 | 22.75 |
| 0.826 | 20.98 | 2.62 | 65.9 | 11 1/2 | V 1/2 | 22 | |
| 0.834 | 21.18 | 2.57 | 66.6 | 11 3/4 | W | ||
| 0.842 | 21.39 | 2.65 | 67.8 | 12 | W 1/2 | 23 | 25 |
| 0.85 | 21.59 | 2.67 | 67.2 | 12 1/4 | X | ||
| 0.858 | 21.79 | 2.70 | 68.5 | 12 1/2 | X 1/2 | 24 | |
| 0.866 | 22.00 | 2.72 | 69.1 | 12 3/4 | Y | 27.5 | |
| 0.874 | 22.20 | 2.75 | 69.7 | 13 | Z | 25 | |
| 0.882 | 22.40 | 2.77 | 70.4 | 13 1/4 | Z 1/2 | 28.75 | |
| 0.89 | 22.61 | 2.80 | 71.0 | 13 1/2 | 26 | ||
| 0.898 | 22.81 | 2.82 | 71.7 | 13 3/4 | Z1 | ||
| 0.906 | 23.01 | 2.85 | 72.3 | 14 | 27 | ||
| 0.914 | 23.22 | 2.87 | 72.9 | 14 1/4 | Z2 | ||
| 0.922 | 23.42 | 2.90 | 73.6 | 14 1/2 | Z3 | ||
| 0.93 | 23.62 | 2.92 | 74.2 | 14 3/4 | |||
| 0.938 | 23.83 | 2.95 | 74.8 | 15 | Z4 | ||
| 0.946 | 24.03 | 2.97 | 75.5 | 15 1/4 | |||
| 0.954 | 24.23 | 3.00 | 76.1 | 15 1/2 | |||
| 0.962 | 24.43 | 3.02 | 76.8 | 15 3/4 | |||
| 0.97 | 24.64 | 77.4 | 16 | ||||