{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "awg-wire-gauge-table-astm-b258",
 "name": "AWG wire gauge table (ASTM B258): 4/0 to 56 AWG, diameter in mils, inches and mm, area in circular mils and mm²",
 "kind": "standard",
 "category": "Electronics",
 "group": "Wiring & connectors",
 "year": null,
 "question": "What is the diameter of 12 AWG, 14 AWG or 10 AWG wire in inches and mm?",
 "tags": [
  "awg",
  "wire gauge",
  "wire size",
  "astm b258",
  "conductor diameter",
  "wire diameter",
  "brown and sharpe",
  "tool"
 ],
 "aliases": [
  "awg to mm",
  "awg to mm2",
  "12 awg diameter",
  "14 awg wire diameter",
  "10 awg diameter mm",
  "18 awg wire diameter",
  "awg wire size chart",
  "awg to inches",
  "22 awg diameter",
  "24 awg wire diameter mm",
  "wire gauge to mm",
  "20 awg diameter",
  "16 awg wire diameter",
  "0000 awg diameter",
  "awg to circular mils",
  "26 awg diameter",
  "30 awg wire diameter",
  "american wire gauge table",
  "brown and sharpe gauge"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "not-scanned",
 "les": false,
 "free_files": 0,
 "url": "https://xemstudio.com/objects/awg-wire-gauge-table-astm-b258/",
 "sheet_txt": "https://xemstudio.com/objects/awg-wire-gauge-table-astm-b258/sheet.txt",
 "sheet": {
  "basis": "ASTM B258 Table 1 (nominal diameters and cross-sectional areas of AWG solid round wires at 20 °C), all 60 rows as printed; numbers only",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "ASTM B258 Table 1: standard nominal diameters and cross-sectional areas of AWG sizes of solid round wire at 20 °C, 4/0 to 56 AWG, as printed in the iTeh sample of ASTM B258-02. One mil is 0.001 in. The inch column is the mil value divided by 1000 (the standard prints mils and mm); the other columns are as printed. Per the standard, 4/0 to 44 AWG diameters are given to no more than four significant figures and 0.1 mil, 45 to 56 AWG to 0.01 mil; diameters are calculated from the AWG law and rounded only at the end.",
   "Xem check: the printed mil values for 4/0 to 44 agree with the AWG law d = 0.005 in × 92^((36 − n) / 39) (n is the gauge number, with 1/0 = 0, 2/0 = -1, 3/0 = -2, 4/0 = -3) to within the standard's rounding, and every mm value but one (flagged below) equals mils × 0.0254 within its rounding. Each step down in gauge number is a factor of 92^(1/39) = 1.1229 in diameter; six gauges halve the diameter (about) and three gauges halve the area.",
   "One printed value is inconsistent: the sample's mm diameter for 19 AWG is 0.904, but its own 35.9 mils is 0.912 mm and its area 0.653 mm² is that of a 0.912 mm wire (a 0.904 mm wire would be 0.642 mm²). The printed number is kept and flagged in the table; use 0.912 mm unless you have the standard in hand. Those are the solid conductor sizes. A stranded conductor of the same AWG has a larger overall diameter (7 strands = three strand diameters across, 19 strands = five, 37 = seven, and so on) and the strand diameters are in the stranding standards, not in B258. Insulated outside diameters differ by insulation type and maker: no maker-published table that could be read is on this page. Sized tubes for wires are on the heat-shrink and cable-gland pages.",
   "A different series: SWG (British) and metric mm² sizes are on their own pages; sheet metal gauge numbers are not wire gauge numbers (the aluminium and brass sheet gauge uses the same AWG / Brown & Sharpe diameters, steel sheet gauge does not).",
   "The standard is sold by ASTM; the table here is the one in the sample the publisher gives out. No files: wire is a plain cylinder."
  ],
  "table": {
   "columns": [
    "AWG",
    "diameter (mils)",
    "diameter (in, mils ÷ 1000)",
    "diameter (mm)",
    "area (circular mils)",
    "area (mm²)"
   ],
   "rows": [
    [
     "4/0",
     "460.0",
     "0.4600",
     "11.684",
     "211600",
     "107.2"
    ],
    [
     "3/0",
     "409.6",
     "0.4096",
     "10.404",
     "167800",
     "85.0"
    ],
    [
     "2/0",
     "364.8",
     "0.3648",
     "9.26",
     "133100",
     "67.4"
    ],
    [
     "1/0",
     "324.9",
     "0.3249",
     "8.25",
     "105600",
     "53.5"
    ],
    [
     "1",
     "289.3",
     "0.2893",
     "7.35",
     "83690",
     "42.4"
    ],
    [
     "2",
     "257.6",
     "0.2576",
     "6.54",
     "66360",
     "33.6"
    ],
    [
     "3",
     "229.4",
     "0.2294",
     "5.82",
     "52620",
     "26.7"
    ],
    [
     "4",
     "204.3",
     "0.2043",
     "5.19",
     "41740",
     "21.1"
    ],
    [
     "5",
     "181.9",
     "0.1819",
     "4.62",
     "33090",
     "16.8"
    ],
    [
     "6",
     "162.0",
     "0.1620",
     "4.11",
     "26240",
     "13.3"
    ],
    [
     "7",
     "144.3",
     "0.1443",
     "3.67",
     "20820",
     "10.6"
    ],
    [
     "8",
     "128.5",
     "0.1285",
     "3.26",
     "16510",
     "8.37"
    ],
    [
     "9",
     "114.4",
     "0.1144",
     "2.91",
     "13090",
     "6.63"
    ],
    [
     "10",
     "101.9",
     "0.1019",
     "2.59",
     "10380",
     "5.26"
    ],
    [
     "11",
     "90.7",
     "0.0907",
     "2.30",
     "8230",
     "4.17"
    ],
    [
     "12",
     "80.8",
     "0.0808",
     "2.05",
     "6530",
     "3.31"
    ],
    [
     "13",
     "72.0",
     "0.0720",
     "1.83",
     "5180",
     "2.63"
    ],
    [
     "14",
     "64.1",
     "0.0641",
     "1.63",
     "4110",
     "2.08"
    ],
    [
     "15",
     "57.1",
     "0.0571",
     "1.45",
     "3260",
     "1.65"
    ],
    [
     "16",
     "50.8",
     "0.0508",
     "1.29",
     "2580",
     "1.31"
    ],
    [
     "17",
     "45.3",
     "0.0453",
     "1.15",
     "2050",
     "1.04"
    ],
    [
     "18",
     "40.3",
     "0.0403",
     "1.02",
     "1620",
     "0.823"
    ],
    [
     "19",
     "35.9",
     "0.0359",
     "0.904 (as printed; mils × 0.0254 = 0.912)",
     "1290",
     "0.653"
    ],
    [
     "20",
     "32.0",
     "0.0320",
     "0.813",
     "1020",
     "0.519"
    ],
    [
     "21",
     "28.5",
     "0.0285",
     "0.724",
     "812",
     "0.412"
    ],
    [
     "22",
     "25.3",
     "0.0253",
     "0.643",
     "640",
     "0.324"
    ],
    [
     "23",
     "22.6",
     "0.0226",
     "0.574",
     "511",
     "0.259"
    ],
    [
     "24",
     "20.1",
     "0.0201",
     "0.511",
     "404",
     "0.205"
    ],
    [
     "25",
     "17.9",
     "0.0179",
     "0.455",
     "320",
     "0.162"
    ],
    [
     "26",
     "15.9",
     "0.0159",
     "0.404",
     "253",
     "0.128"
    ],
    [
     "27",
     "14.2",
     "0.0142",
     "0.361",
     "202",
     "0.102"
    ],
    [
     "28",
     "12.6",
     "0.0126",
     "0.320",
     "159",
     "0.0804"
    ],
    [
     "29",
     "11.3",
     "0.0113",
     "0.287",
     "128",
     "0.0647"
    ],
    [
     "30",
     "10.0",
     "0.0100",
     "0.254",
     "100",
     "0.0507"
    ],
    [
     "31",
     "8.9",
     "0.0089",
     "0.226",
     "79.2",
     "0.0401"
    ],
    [
     "32",
     "8.0",
     "0.0080",
     "0.203",
     "64.0",
     "0.0324"
    ],
    [
     "33",
     "7.1",
     "0.0071",
     "0.180",
     "50.4",
     "0.0255"
    ],
    [
     "34",
     "6.3",
     "0.0063",
     "0.160",
     "39.7",
     "0.0201"
    ],
    [
     "35",
     "5.6",
     "0.0056",
     "0.142",
     "31.4",
     "0.0159"
    ],
    [
     "36",
     "5.0",
     "0.0050",
     "0.127",
     "25.0",
     "0.0127"
    ],
    [
     "37",
     "4.5",
     "0.0045",
     "0.114",
     "20.2",
     "0.0103"
    ],
    [
     "38",
     "4.0",
     "0.0040",
     "0.102",
     "16.0",
     "0.00811"
    ],
    [
     "39",
     "3.5",
     "0.0035",
     "0.0890",
     "12.2",
     "0.00621"
    ],
    [
     "40",
     "3.1",
     "0.0031",
     "0.0787",
     "9.61",
     "0.00487"
    ],
    [
     "41",
     "2.8",
     "0.00280",
     "0.0711",
     "7.84",
     "0.00397"
    ],
    [
     "42",
     "2.5",
     "0.00250",
     "0.0635",
     "6.25",
     "0.00317"
    ],
    [
     "43",
     "2.2",
     "0.00220",
     "0.0559",
     "4.84",
     "0.00245"
    ],
    [
     "44",
     "2.0",
     "0.00200",
     "0.0508",
     "4.00",
     "0.00203"
    ],
    [
     "45",
     "1.76",
     "0.00176",
     "0.0447",
     "3.10",
     "0.00157"
    ],
    [
     "46",
     "1.57",
     "0.00157",
     "0.0399",
     "2.46",
     "0.00125"
    ],
    [
     "47",
     "1.40",
     "0.00140",
     "0.0356",
     "1.96",
     "0.000993"
    ],
    [
     "48",
     "1.24",
     "0.00124",
     "0.0315",
     "1.54",
     "0.000779"
    ],
    [
     "49",
     "1.11",
     "0.00111",
     "0.0282",
     "1.23",
     "0.000624"
    ],
    [
     "50",
     "0.99",
     "0.00099",
     "0.0252",
     "0.980",
     "0.000497"
    ],
    [
     "51",
     "0.88",
     "0.00088",
     "0.0224",
     "0.774",
     "0.000392"
    ],
    [
     "52",
     "0.78",
     "0.00078",
     "0.0198",
     "0.608",
     "0.000308"
    ],
    [
     "53",
     "0.70",
     "0.00070",
     "0.0178",
     "0.490",
     "0.000248"
    ],
    [
     "54",
     "0.62",
     "0.00062",
     "0.0158",
     "0.384",
     "0.000195"
    ],
    [
     "55",
     "0.55",
     "0.00055",
     "0.0140",
     "0.302",
     "0.000153"
    ],
    [
     "56",
     "0.49",
     "0.00049",
     "0.0125",
     "0.240",
     "0.000122"
    ]
   ]
  }
 },
 "sheet_text": "AWG wire gauge table (ASTM B258): 4/0 to 56 AWG, diameter in mils, inches and mm, area in circular mils and mm² — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/awg-wire-gauge-table-astm-b258/  (sheet CC BY 4.0)\nBasis: ASTM B258 Table 1 (nominal diameters and cross-sectional areas of AWG solid round wires at 20 °C), all 60 rows as printed; numbers only\nCatalog version: 2026-10-20\n\nSizes: see table below\n- ASTM B258 Table 1: standard nominal diameters and cross-sectional areas of AWG sizes of solid round wire at 20 °C, 4/0 to 56 AWG, as printed in the iTeh sample of ASTM B258-02. One mil is 0.001 in. The inch column is the mil value divided by 1000 (the standard prints mils and mm); the other columns are as printed. Per the standard, 4/0 to 44 AWG diameters are given to no more than four significant figures and 0.1 mil, 45 to 56 AWG to 0.01 mil; diameters are calculated from the AWG law and rounded only at the end.\n- Xem check: the printed mil values for 4/0 to 44 agree with the AWG law d = 0.005 in × 92^((36 − n) / 39) (n is the gauge number, with 1/0 = 0, 2/0 = -1, 3/0 = -2, 4/0 = -3) to within the standard's rounding, and every mm value but one (flagged below) equals mils × 0.0254 within its rounding. Each step down in gauge number is a factor of 92^(1/39) = 1.1229 in diameter; six gauges halve the diameter (about) and three gauges halve the area.\n- One printed value is inconsistent: the sample's mm diameter for 19 AWG is 0.904, but its own 35.9 mils is 0.912 mm and its area 0.653 mm² is that of a 0.912 mm wire (a 0.904 mm wire would be 0.642 mm²). The printed number is kept and flagged in the table; use 0.912 mm unless you have the standard in hand. Those are the solid conductor sizes. A stranded conductor of the same AWG has a larger overall diameter (7 strands = three strand diameters across, 19 strands = five, 37 = seven, and so on) and the strand diameters are in the stranding standards, not in B258. Insulated outside diameters differ by insulation type and maker: no maker-published table that could be read is on this page. Sized tubes for wires are on the heat-shrink and cable-gland pages.\n- A different series: SWG (British) and metric mm² sizes are on their own pages; sheet metal gauge numbers are not wire gauge numbers (the aluminium and brass sheet gauge uses the same AWG / Brown & Sharpe diameters, steel sheet gauge does not).\n- The standard is sold by ASTM; the table here is the one in the sample the publisher gives out. No files: wire is a plain cylinder.\n\nAWG  diameter (mils)  diameter (in, mils ÷ 1000)  diameter (mm)  area (circular mils)  area (mm²)\n4/0  460.0  0.4600  11.684  211600  107.2\n3/0  409.6  0.4096  10.404  167800  85.0\n2/0  364.8  0.3648  9.26  133100  67.4\n1/0  324.9  0.3249  8.25  105600  53.5\n1  289.3  0.2893  7.35  83690  42.4\n2  257.6  0.2576  6.54  66360  33.6\n3  229.4  0.2294  5.82  52620  26.7\n4  204.3  0.2043  5.19  41740  21.1\n5  181.9  0.1819  4.62  33090  16.8\n6  162.0  0.1620  4.11  26240  13.3\n7  144.3  0.1443  3.67  20820  10.6\n8  128.5  0.1285  3.26  16510  8.37\n9  114.4  0.1144  2.91  13090  6.63\n10  101.9  0.1019  2.59  10380  5.26\n11  90.7  0.0907  2.30  8230  4.17\n12  80.8  0.0808  2.05  6530  3.31\n13  72.0  0.0720  1.83  5180  2.63\n14  64.1  0.0641  1.63  4110  2.08\n15  57.1  0.0571  1.45  3260  1.65\n16  50.8  0.0508  1.29  2580  1.31\n17  45.3  0.0453  1.15  2050  1.04\n18  40.3  0.0403  1.02  1620  0.823\n19  35.9  0.0359  0.904 (as printed; mils × 0.0254 = 0.912)  1290  0.653\n20  32.0  0.0320  0.813  1020  0.519\n21  28.5  0.0285  0.724  812  0.412\n22  25.3  0.0253  0.643  640  0.324\n23  22.6  0.0226  0.574  511  0.259\n24  20.1  0.0201  0.511  404  0.205\n25  17.9  0.0179  0.455  320  0.162\n26  15.9  0.0159  0.404  253  0.128\n27  14.2  0.0142  0.361  202  0.102\n28  12.6  0.0126  0.320  159  0.0804\n29  11.3  0.0113  0.287  128  0.0647\n30  10.0  0.0100  0.254  100  0.0507\n31  8.9  0.0089  0.226  79.2  0.0401\n32  8.0  0.0080  0.203  64.0  0.0324\n33  7.1  0.0071  0.180  50.4  0.0255\n34  6.3  0.0063  0.160  39.7  0.0201\n35  5.6  0.0056  0.142  31.4  0.0159\n36  5.0  0.0050  0.127  25.0  0.0127\n37  4.5  0.0045  0.114  20.2  0.0103\n38  4.0  0.0040  0.102  16.0  0.00811\n39  3.5  0.0035  0.0890  12.2  0.00621\n40  3.1  0.0031  0.0787  9.61  0.00487\n41  2.8  0.00280  0.0711  7.84  0.00397\n42  2.5  0.00250  0.0635  6.25  0.00317\n43  2.2  0.00220  0.0559  4.84  0.00245\n44  2.0  0.00200  0.0508  4.00  0.00203\n45  1.76  0.00176  0.0447  3.10  0.00157\n46  1.57  0.00157  0.0399  2.46  0.00125\n47  1.40  0.00140  0.0356  1.96  0.000993\n48  1.24  0.00124  0.0315  1.54  0.000779\n49  1.11  0.00111  0.0282  1.23  0.000624\n50  0.99  0.00099  0.0252  0.980  0.000497\n51  0.88  0.00088  0.0224  0.774  0.000392\n52  0.78  0.00078  0.0198  0.608  0.000308\n53  0.70  0.00070  0.0178  0.490  0.000248\n54  0.62  0.00062  0.0158  0.384  0.000195\n55  0.55  0.00055  0.0140  0.302  0.000153\n56  0.49  0.00049  0.0125  0.240  0.000122\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- ASTM (iTeh sample copy): ASTM B258-02: Table 1, standard nominal diameters and cross-sectional areas of AWG sizes of solid round wires at 20 C, 4/0 to 56 — web — Publisher's page; dimensions are facts — https://cdn.standards.iteh.ai/samples/959/0248539ea2744b1b909bfde58d575ab1/ASTM-B258-02.pdf\n- ASTM: ASTM B258 Standard Specification for Standard Nominal Diameters and Cross-Sectional Areas of AWG Sizes of Solid Round Wires Used as Electrical Conductors — web — Standards body's page; dimensions are facts — https://webstore.ansi.org/standards/astm/astmb25802\n\nNo true-size file yet: the published figures do not fix the whole shape; a measured scan is planned.\nAPI: https://xemstudio.com/api/geometry?object=awg-wire-gauge-table-astm-b258\n",
 "sources": [
  {
   "publisher": "ASTM (iTeh sample copy)",
   "title": "ASTM B258-02: Table 1, standard nominal diameters and cross-sectional areas of AWG sizes of solid round wires at 20 C, 4/0 to 56",
   "url": "https://cdn.standards.iteh.ai/samples/959/0248539ea2744b1b909bfde58d575ab1/ASTM-B258-02.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "ASTM",
   "title": "ASTM B258 Standard Specification for Standard Nominal Diameters and Cross-Sectional Areas of AWG Sizes of Solid Round Wires Used as Electrical Conductors",
   "url": "https://webstore.ansi.org/standards/astm/astmb25802",
   "formats": [
    "web"
   ],
   "license": "Standards body's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
 "xem": {
  "status": "not-scanned",
  "sheet_free": true,
  "mesh_price_usd": null,
  "step_price_usd": null,
  "tolerance_mm": null
 },
 "related": [
  "swg-standard-wire-gauge-table",
  "metric-wire-sizes-iec-60228-mm2-awg",
  "sheet-metal-gauge-chart-steel-galvanized-stainless-aluminum",
  "music-wire-sizes",
  "ring-tongue-terminals-by-stud-and-wire",
  "wago-221-lever-connectors",
  "heat-shrink-tubing-sizes",
  "cable-and-plug-sizes",
  "wire-end-ferrules-din-46228",
  "compression-cable-lugs-din-46235"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no tolerance added)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no tolerance added. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn. Typical accuracy by process and ISO 286 fits: https://xemstudio.com/tolerances/",
 "mating": [
  {
   "feature": "solid wire of a given AWG",
   "exact": "diameter per the table, 20 °C (12 AWG 2.05 mm, 14 AWG 1.63 mm, 18 AWG 1.02 mm)",
   "mates": "a clamp terminal, ferrule or crimp barrel sized for that AWG (the terminal maker's table governs)",
   "fit": "designed",
   "files": "all"
  }
 ],
 "fit_classes": {
  "press": "stays put: pin, tube, bearing or magnet held by interference. ISO 286 equivalent: H7/p6 (locational interference) or tighter.",
  "slide": "assembles by hand and is held by a grub, pinch or clamp: shaft in a hub, rod in a socket, spigot in a bore. ISO 286 equivalent: H7/g6 or H7/h6.",
  "run": "turns or slides in use: pin in a link, rod through a guide. ISO 286 equivalent: H8/f7 (close running).",
  "socket": "large sliding fit: syringe barrel, sleeve, bobbin in a bore. ISO 286 equivalent: H9/d9 (free running) or looser.",
  "clamp": "split part that closes on the mating part with screws: make it at size.",
  "designed": "a gap that is part of the design (piston fit option, displacer gap, air gap): do not change."
 },
 "faq": [
  {
   "q": "What is the diameter of 12 AWG wire?",
   "a": "0.0808 in (80.8 mils, 2.05 mm), area 6530 circular mils or 3.31 mm² for solid wire (ASTM B258)."
  },
  {
   "q": "What is the diameter of 14 AWG wire?",
   "a": "0.0641 in (1.63 mm), 2.08 mm² for solid wire."
  },
  {
   "q": "How big is 10 AWG in mm?",
   "a": "2.59 mm diameter, 5.26 mm² area, solid."
  },
  {
   "q": "What is 4/0 AWG in mm?",
   "a": "11.684 mm (0.4600 in), 107.2 mm² area, solid."
  }
 ],
 "files_license": null,
 "offers": [],
 "markdown": "https://xemstudio.com/objects/awg-wire-gauge-table-astm-b258/index.md"
}