{
  "source": "https://mysizecharts.com",
  "license": "Free to use with attribution to SizeCharts.",
  "note": "Conversion tables checked against published international sizing standards.",
  "updated": "2026-07-02",
  "category": "ring",
  "unit": "millimetres",
  "sizes": [
    {
      "us": "3",
      "uk": "F",
      "eu": "44",
      "jp": "4",
      "diameterMm": 14.1,
      "circumferenceMm": 44.2
    },
    {
      "us": "3.5",
      "uk": "G",
      "eu": "45",
      "jp": "5",
      "diameterMm": 14.5,
      "circumferenceMm": 45.5
    },
    {
      "us": "4",
      "uk": "H",
      "eu": "47",
      "jp": "7",
      "diameterMm": 14.9,
      "circumferenceMm": 46.8
    },
    {
      "us": "4.5",
      "uk": "I",
      "eu": "48",
      "jp": "8",
      "diameterMm": 15.3,
      "circumferenceMm": 48
    },
    {
      "us": "5",
      "uk": "J",
      "eu": "49",
      "jp": "9",
      "diameterMm": 15.7,
      "circumferenceMm": 49.3
    },
    {
      "us": "5.5",
      "uk": "K",
      "eu": "50",
      "jp": "10",
      "diameterMm": 16.1,
      "circumferenceMm": 50.6
    },
    {
      "us": "6",
      "uk": "L",
      "eu": "52",
      "jp": "12",
      "diameterMm": 16.5,
      "circumferenceMm": 51.9
    },
    {
      "us": "6.5",
      "uk": "M",
      "eu": "53",
      "jp": "13",
      "diameterMm": 16.9,
      "circumferenceMm": 53.1
    },
    {
      "us": "7",
      "uk": "N",
      "eu": "54",
      "jp": "14",
      "diameterMm": 17.3,
      "circumferenceMm": 54.4
    },
    {
      "us": "7.5",
      "uk": "O",
      "eu": "56",
      "jp": "15",
      "diameterMm": 17.7,
      "circumferenceMm": 55.7
    },
    {
      "us": "8",
      "uk": "P",
      "eu": "57",
      "jp": "16",
      "diameterMm": 18.1,
      "circumferenceMm": 57
    },
    {
      "us": "8.5",
      "uk": "Q",
      "eu": "58",
      "jp": "17",
      "diameterMm": 18.5,
      "circumferenceMm": 58.3
    },
    {
      "us": "9",
      "uk": "R",
      "eu": "59",
      "jp": "18",
      "diameterMm": 19,
      "circumferenceMm": 59.5
    },
    {
      "us": "9.5",
      "uk": "S",
      "eu": "61",
      "jp": "19",
      "diameterMm": 19.4,
      "circumferenceMm": 60.8
    },
    {
      "us": "10",
      "uk": "T",
      "eu": "62",
      "jp": "20",
      "diameterMm": 19.8,
      "circumferenceMm": 62.1
    },
    {
      "us": "10.5",
      "uk": "U",
      "eu": "63",
      "jp": "22",
      "diameterMm": 20.2,
      "circumferenceMm": 63.4
    },
    {
      "us": "11",
      "uk": "V",
      "eu": "64",
      "jp": "23",
      "diameterMm": 20.6,
      "circumferenceMm": 64.6
    },
    {
      "us": "11.5",
      "uk": "W",
      "eu": "66",
      "jp": "24",
      "diameterMm": 21,
      "circumferenceMm": 65.9
    },
    {
      "us": "12",
      "uk": "X",
      "eu": "67",
      "jp": "25",
      "diameterMm": 21.4,
      "circumferenceMm": 67.2
    },
    {
      "us": "12.5",
      "uk": "Y",
      "eu": "68",
      "jp": "26",
      "diameterMm": 21.8,
      "circumferenceMm": 68.5
    },
    {
      "us": "13",
      "uk": "Z",
      "eu": "69",
      "jp": "27",
      "diameterMm": 22.2,
      "circumferenceMm": 69.7
    }
  ]
}