Utility Cable Sizing Guide

Compact Stranding

Conductor Sizes (Cu/Al) 175 Mils – 15 kV Ø 220 Mils – 15 kV Ø 260 Mils – 25 kV Ø 345 Mils – 35 kV Ø
Cable Size Nominal O.D. Over Insulation (+30 Mils) Over Shielding (+50 Mils) Over Insulation (+30 Mils) Over Shielding (+50 Mils) Over Insulation (+30 Mils) Over Shielding (+50 Mils) Over Insulation (+30 Mils) Over Shielding (+50 Mils)
2 AWG 0.268″ 680 mils 780 mils 770 mils 870 mils – – – –
1 AWG 0.299″ 710 mils 810 mils 800 mils 900 mils 880 mils 980 mils – –
1/0 AWG 0.336″ 745 mils 845 mils 835 mils 935 mils 915 mils 1015 mils 1085 mils 1205 mils
2/0 AWG 0.376″ 785 mils 885 mils 875 mils 975 mils 955 mils 1055 mils 1125 mils 1245 mils
3/0 AWG 0.423″ 835 mils 935 mils 925 mils 1025 mils 1005 mils 1105 mils 1175 mils 1295 mils
4/0 AWG 0.475″ 885 mils 985 mils 975 mils 1075 mils 1055 mils 1175 mils 1225 mils 1345 mils
250 kcmil 0.520″ 940 mils 1040 mils 1030 mils 1130 mils 1120 mils 1240 mils 1295 mils 1415 mils
350 kcmil 0.616″ 1035 mils 1155 mils 1125 mils 1245 mils 1215 mils 1335 mils 1390 mils 1510 mils
500 kcmil 0.736″ 1155 mils 1275 mils 1245 mils 1365 mils 1335 mils 1455 mils 1510 mils 1630 mils
600 kcmil 0.813″ 1245 mils 1365 mils 1335 mils 1455 mils 1425 mils 1545 mils 1600 mils 1760 mils
700 kcmil 0.877″ 1305 mils 1425 mils 1395 mils 1515 mils 1485 mils 1605 mils 1660 mils 1820 mils
750 kcmil 0.908″ 1340 mils 1460 mils 1430 mils 1550 mils 1520 mils 1640 mils 1695 mils 1855 mils
800 kcmil 0.938″ 1370 mils 1490 mils 1460 mils 1580 mils 1550 mils 1710 mils 1725 mils 1885 mils
900 kcmil 0.999″ 1430 mils 1550 mils 1520 mils 1640 mils 1610 mils 1770 mils 1785 mils 1945 mils
1000 kcmil 1.060″ 1490 mils 1610 mils 1580 mils 1740 mils 1670 mils 1830 mils 1845 mils 2005 mils

Compressed Stranding

Conductor Sizes (Cu/Al) 175 Mils – 15 kV Ø 220 Mils – 15 kV Ø 260 Mils – 25 kV Ø 345 Mils – 35 kV Ø
Cable Size Nominal O.D. Over Insulation (+30 Mils) Over Shielding (+50 Mils) Over Insulation (+30 Mils) Over Shielding (+50 Mils) Over Insulation (+30 Mils) Over Shielding (+50 Mils) Over Insulation (+30 Mils) Over Shielding (+50 Mils)
2 AWG 0.283″ 695 mils 795 mils 785 mils 885 mils – – – –
1 AWG 0.322″ 730 mils 830 mils 820 mils 920 mils 900 mils 1000 mils – –
1/0 AWG 0.362″ 770 mils 870 mils 860 mils 960 mils 940 mils 1040 mils 1110 mils 1230 mils
2/0 AWG 0.405″ 815 mils 915 mils 905 mils 1005 mils 985 mils 1085 mils 1155 mils 1275 mils
3/0 AWG 0.456″ 865 mils 965 mils 955 mils 1055 mils 1035 mils 1155 mils 1205 mils 1325 mils
4/0 AWG 0.512″ 920 mils 1020 mils 1010 mils 1110 mils 1090 mils 1210 mils 1260 mils 1380 mils
250 kcmil 0.558″ 980 mils 1080 mils 1070 mils 1190 mils 1160 mils 1280 mils 1335 mils 1455 mils
350 kcmil 0.660″ 1080 mils 1200 mils 1170 mils 1290 mils 1260 mils 1380 mils 1435 mils 1555 mils
500 kcmil 0.789″ 1210 mils 1330 mils 1300 mils 1420 mils 1390 mils 1510 mils 1565 mils 1725 mils
600 kcmil 0.866″ 1295 mils 1415 mils 1385 mils 1505 mils 1475 mils 1595 mils 1650 mils 1810 mils
700 kcmil 0.935″ 1365 mils 1485 mils 1455 mils 1575 mils 1545 mils 1705 mils 1720 mils 1880 mils
750 kcmil 0.968″ 1400 mils 1520 mils 1490 mils 1610 mils 1580 mils 1740 mils 1755 mils 1915 mils
800 kcmil 1.000″ 1430 mils 1550 mils 1520 mils 1640 mils 1610 mils 1770 mils 1785 mils 1945 mils
900 kcmil 1.061″ 1490 mils 1610 mils 1580 mils 1740 mils 1670 mils 1830 mils 1845 mils 2005 mils
1000 kcmil 1.117″ 1545 mils 1705 mils 1635 mils 1795 mils 1725 mils 1885 mils 1900 mils 2060 mils

Concentric Stranding

Conductor Sizes (Cu/Al) 175 Mils – 15 kV Ø 220 Mils – 15 kV Ø 260 Mils – 25 kV Ø 345 Mils – 35 kV Ø
Cable Size Nominal O.D. Over Insulation (+30 Mils) Over Shielding (+50 Mils) Over Insulation (+30 Mils) Over Shielding (+50 Mils) Over Insulation (+30 Mils) Over Shielding (+50 Mils) Over Insulation (+30 Mils) Over Shielding (+50 Mils)
2 AWG (Solid) 0.258″ 670 mils 770 mils 760 mils 860 mils – – – –
2 AWG 0.292″ 700 mils 800 mils 790 mils 890 mils – – – –
1 AWG (Solid) 0.289″ 700 mils 800 mils 790 mils 890 mils 870 mils 970 mils – –
1 AWG 0.332″ 740 mils 840 mils 830 mils 930 mils 910 mils 1010 mils – –
1/0 (Solid) 0.325″ 735 mils 835 mils 825 mils 925 mils 905 mils 1005 mils 1075 mils 1195 mils
1/0 AWG 0.373″ 785 mils 835 mils 875 mils 975 mils 955 mils 1055 mils 1125 mils 1245 mils
2/0 AWG 0.418″ 830 mils 930 mils 920 mils 1020 mils 1000 mils 1100 mils 1170 mils 1290 mils
3/0 AWG 0.470″ 880 mils 980 mils 970 mils 1070 mils 1050 mils 1170 mils 1220 mils 1340 mils
4/0 AWG 0.528″ 940 mils 1040 mils 1030 mils 1130 mils 1110 mils 1230 mils 1280 mils 1400 mils
250 kcmil 0.575″ 995 mils 1095 mils 1085 mils 1205 mils 1175 mils 1295 mils 1350 mils 1470 mils
350 kcmil 0.681″ 1100 mils 1220 mils 1190 mils 1310 mils 1280 mils 1400 mils 1455 mils 1575 mils
500 kcmil 0.813″ 1235 mils 1355 mils 1325 mils 1445 mils 1415 mils 1535 mils 1590 mils 1750 mils
600 kcmil 0.893″ 1325 mils 1445 mils 1415 mils 1535 mils 1505 mils 1625 mils 1680 mils 1840 mils
700 kcmil 0.964″ 1395 mils 1515 mils 1485 mils 1605 mils 1575 mils 1735 mils 1750 mils 1910 mils
750 kcmil 0.998″ 1430 mils 1550 mils 1520 mils 1640 mils 1610 mils 1770 mils 1785 mils 1945 mils
800 kcmil 1.031″ 1460 mils 1580 mils 1550 mils 1710 mils 1640 mils 1800 mils 1815 mils 1975 mils
900 kcmil 1.094″ 1525 mils 1645 mils 1615 mils 1775 mils 1705 mils 1865 mils 1880 mils 2040 mils
1000 kcmil 1.152″ 1580 mils 1740 mils 1670 mils 1830 mils 1760 mils 1920 mils 1935 mils 2095 mils

600V Secondary Cable

Cable Size THHN/THWN Compact Al THHN/THWN XHHW Compact Al XHHW RHW-USE RHH, TWH Compact Al RHH, TWH THHN/THWN Compact Al THHN/THWN XHHW
Insulation NEC O.D. NEC O.D. Insulation NEC O.D. NEC O.D. Insulation NEC O.D. NEC O.D.
6 AWG 35 mils 0.257″ 0.240″ 45 mils 0.282″ 0.260″ 60 mils 0.323″ 0.290″
4 AWG 46 mils 0.328″ 0.305″ 45 mils 0.328″ 0.305″ 60 mils 0.372″ 0.335″
2 AWG 46 mils 0.388″ 0.360″ 45 mils 0.388″ 0.360″ 60 mils 0.433″ 0.390″
1 AWG 57 mils 0.450″ 0.415″ 55 mils 0.450″ 0.425″ 80 mils 0.508″ 0.465″
1/0 AWG 57 mils 0.491″ 0.450″ 55 mils 0.491″ 0.450″ 80 mils 0.549″ 0.500″
2/0 AWG 57 mils 0.537″ 0.495″ 55 mils 0.537″ 0.490″ 80 mils 0.595″ 0.545″
3/0 AWG 57 mils 0.588″ 0.540″ 55 mils 0.588″ 0.540″ 80 mils 0.647″ 0.590″
4/0 AWG 57 mils 0.646″ 0.595″ 55 mils 0.646″ 0.590″ 80 mils 0.705″ 0.645″
250 kcmil 68 mils 0.716″ 0.670″ 65 mils 0.716″ 0.660″ 95 mils 0.788″ 0.725″
300 kcmil 68 mils 0.771″ 0.720″ 65 mils 0.771″ 0.715″ 95 mils 0.843″ 0.775″
350 kcmil 68 mils 0.822″ 0.770″ 65 mils 0.882″ 0.760″ 95 mils 0.895″ 0.820″
500 kcmil 68 mils 0.869″ 0.815″ 65 mils 0.869″ 0.800″ 95 mils 0.942″ 0.865″
600 kcmil 68 mils 0.955″ 0.885″ 65 mils 0.955″ 0.880″ 95 mils 10.040″ 0.965″