The best way to take the size of your finger

is to measure the inside diameter of a ring that fits your finger well.

The measure has to be taken if possible with a precision caliper,

and must be expressed in millimeters.

Tenths of millimeters are also very important:

for example number 15 on the European scale

corresponds to an inside diameter of 17.4 mm.

For the measure refer to the following table:

SIZES |
||||

INSIDE DIAMETER MM. | EUROPEAN | FRENCH | USA | UK |

14.6 mm. | 06 | 46 | 3.75 | H |

14.9 mm. | 07 | 47 | 4.25 | I |

15.2 mm. | 08 | 48 | 4.50 | I-1/2 |

15.6 mm. | 09 | 49 | 4.75 | J |

15.9 mm. | 10 | 50 | 5.25 | K |

16.2 mm. | 11 | 51 | 5.75 | L-1/2 |

16.5 mm. | 12 | 52 | 6.25 | M-1/4 |

16.8 mm. | 13 | 53 | 6.50 | N |

17.1 mm. | 14 | 54 | 6.75 | N-3/4 |

17.4 mm. | 15 | 55 | 7.25 | O-1/4 |

17.8 mm. | 16 | 56 | 7.50 | P |

18.0 mm. | 17 | 57 | 8.00 | Q |

18.4 mm. | 18 | 58 | 8.25 | Q-1/2 |

18.6 mm. | 19 | 59 | 8.75 | R |

19.0 mm. | 20 | 60 | 9.25 | S-1/4 |

19.4 mm. | 21 | 61 | 9.50 | S-3/4 |

19.6 mm. | 22 | 62 | 10.00 | T-1/2 |

20.0 mm. | 23 | 63 | 10.25 | U-1/4 |

20.4 mm. | 24 | 64 | 10.75 | V |

20.7 mm. | 25 | 65 | 11.00 | W |

20.9 mm. | 26 | 66 | 11.25 | X |

21.2 mm. | 27 | 67 | 11.75 | X-3/4 |

21.6 mm. | 28 | 68 | 12.25 | Y-1/2 |

21.9 mm. | 29 | 69 | 12.75 | Z |

22.2 mm. | 30 | 70 | 13.25 | Z-3/4 |