Utility Cable Sizing Guide

Compact Stranding

Conductor Sizes (Cu/Al)220 Mils - 15 kV Ø345 Mils - 35 kV Ø175 Mils - 15 kV Ø260 Mils - 25 kV Ø
Cable SizeNominal 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 AWG0.268″680 mils780 mils770 mils870 mils----
1 AWG0.299″710 mils810 mils800 mils900 mils880 mils980 mils--
1/0 AWG0.336″745 mils845 mils835 mils935 mils915 mils1015 mils1085 mils1205 mils
2/0 AWG0.376″785 mils885 mils875 mils975 mils955 mils1055 mils1125 mils1245 mils
3/0 AWG0.423″835 mils935 mils925 mils1025 mils1005 mils1105 mils1175 mils1295 mils
4/0 AWG0.475″885 mils985 mils975 mils1075 mils1055 mils1175 mils1225 mils1345 mils
250 kcmil0.520″940 mils1040 mils1030 mils1130 mils1120 mils1240 mils1295 mils1415 mils
350 kcmil0.616″1035 mils1155 mils1125 mils1245 mils1215 mils1335 mils1390 mils1510 mils
500 kcmil0.736″1155 mils1275 mils1245 mils1365 mils1335 mils1455 mils1510 mils1630 mils
600 kcmil0.813″1245 mils1365 mils1335 mils1455 mils1425 mils1545 mils1600 mils1760 mils
700 kcmil0.877″1305 mils1425 mils1395 mils1515 mils1485 mils1605 mils1660 mils1820 mils
750 kcmil0.908″1340 mils1460 mils1430 mils1550 mils1520 mils1640 mils1695 mils1855 mils
800 kcmil0.938″1370 mils1490 mils1460 mils1580 mils1550 mils1710 mils1725 mils1885 mils
900 kcmil0.999″1430 mils1550 mils1520 mils1640 mils1610 mils1770 mils1785 mils1945 mils
1000 kcmil1.060″1490 mils1610 mils1580 mils1740 mils1670 mils1830 mils1845 mils2005 mils

 

Compressed Stranding

Conductor Sizes (Cu/Al)220 Mils - 15 kV Ø345 Mils - 35 kV Ø175 Mils - 15 kV Ø260 Mils - 25 kV Ø
Cable SizeNominal 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 AWG0.283″695 mils795 mils785 mils885 mils----
1 AWG0.322″730 mils830 mils820 mils920 mils900 mils1000 mils--
1/0 AWG0.362″ 770 mils870 mils860 mils960 mils940 mils1040 mils1110 mils1230 mils
2/0 AWG0.405″815 mils915 mils905 mils1005 mils985 mils1085 mils1155 mils1275 mils
3/0 AWG0.456″865 mils965 mils955 mils1055 mils1035 mils1155 mils1205 mils1325 mils
4/0 AWG0.512″920 mils1020 mils1010 mils1110 mils1090 mils1210 mils1260 mils1380 mils
250 kcmil0.558″980 mils1080 mils1070 mils1190 mils1160 mils1280 mils1335 mils1455 mils
350 kcmil0.660″1080 mils1200 mils1170 mils1290 mils1260 mils1380 mils1435 mils1555 mils
500 kcmil0.789″1210 mils1330 mils1300 mils1420 mils1390 mils1510 mils1565 mils1725 mils
600 kcmil0.866″1295 mils1415 mils1385 mils1505 mils1475 mils1595 mils1650 mils1810 mils
700 kcmil0.935″1365 mils1485 mils1455 mils1575 mils1545 mils1705 mils1720 mils1880 mils
750 kcmil0.968″1400 mils1520 mils1490 mils1610 mils1580 mils1740 mils1755 mils1915 mils
800 kcmil1.000″1430 mils1550 mils1520 mils1640 mils1610 mils1770 mils1785 mils1945 mils
900 kcmil1.061″1490 mils1610 mils1580 mils1740 mils1670 mils1830 mils1845 mils2005 mils
1000 kcmil1.117″1545 mils1705 mils1635 mils1795 mils1725 mils1885 mils1900 mils2060 mils

 

Concentric Stranding

Conductor Sizes (Cu/Al)220 Mils - 15 kV Ø345 Mils - 35 kV Ø175 Mils - 15 kV Ø260 Mils - 25 kV Ø
Cable SizeNominal 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 mils770 mils760 mils860 mils----
2 AWG0.292″700 mils800 mils790 mils890 mils----
1 AWG (Solid)0.289″700 mils800 mils790 mils890 mils870 mils 970 mils--
1 AWG0.332″740 mils840 mils830 mils930 mils910 mils1010 mils--
1/0 (Solid)0.325″735 mils835 mils825 mils925 mils905 mils1005 mils1075 mils1195 mils
1/0 AWG0.373″785 mils835 mils875 mils975 mils955 mils1055 mils1125 mils1245 mils
2/0 AWG0.418″830 mils930 mils920 mils1020 mils1000 mils1100 mils1170 mils1290 mils
3/0 AWG0.470″880 mils980 mils970 mils1070 mils1050 mils1170 mils1220 mils1340 mils
4/0 AWG0.528″940 mils1040 mils1030 mils1130 mils1110 mils1230 mils1280 mils1400 mils
250 kcmil0.575″995 mils1095 mils1085 mils1205 mils1175 mils1295 mils1350 mils1470 mils
350 kcmil0.681″1100 mils1220 mils1190 mils1310 mils1280 mils1400 mils1455 mils1575 mils
500 kcmil0.813″1235 mils1355 mils1325 mils1445 mils1415 mils1535 mils1590 mils1750 mils
600 kcmil0.893″1325 mils1445 mils1415 mils1535 mils1505 mils1625 mils1680 mils1840 mils
700 kcmil0.964″1395 mils1515 mils1485 mils1605 mils1575 mils1735 mils1750 mils1910 mils
750 kcmil0.998″1430 mils1550 mils1520 mils1640 mils1610 mils1770 mils1785 mils1945 mils
800 kcmil1.031″1460 mils1580 mils1550 mils1710 mils1640 mils1800 mils1815 mils1975 mils
900 kcmil1.094″1525 mils1645 mils1615 mils1775 mils1705 mils1865 mils1880 mils2040 mils
1000 kcmil1.152″1580 mils1740 mils1670 mils1830 mils1760 mils1920 mils1935 mils2095 mils

 

600V Secondary Cable

Cable SizeTHHN/THWNXHHWCompact Al XHHWCompact Al RHH, TWHTHHN/THWNXHHW
InsulationNEC O.D.NEC O.D.InsulationNEC O.D.NEC O.D.InsulationNEC O.D.NEC O.D.
6 AWG35 mils0.257″0.240″45 mils0.282″0.260″60 mils0.323″0.290″
4 AWG46 mils0.328″0.305″45 mils0.328″0.305″60 mils0.372″0.335″
2 AWG46 mils0.388″0.360″45 mils0.388″0.360″60 mils0.433″0.390″
1 AWG57 mils0.450″0.415″55 mils0.450″0.425″80 mils0.508″0.465″
1/0 AWG57 mils0.491″0.450″55 mils0.491″0.450″80 mils0.549″0.500″
2/0 AWG57 mils0.537″0.495″55 mils0.537″0.490″80 mils0.595″0.545″
3/0 AWG57 mils0.588″0.540″55 mils0.588″0.540″80 mils0.647″0.590″
4/0 AWG57 mils0.646″0.595″55 mils0.646″0.590″80 mils0.705″0.645″
250 kcmil68 mils0.716″0.670″65 mils0.716″0.660″95 mils0.788″0.725″
300 kcmil68 mils0.771″0.720″65 mils0.771″0.715″95 mils0.843″0.775″
350 kcmil68 mils0.822″0.770″65 mils0.882″0.760″95 mils0.895″0.820″
500 kcmil68 mils0.869″0.815″65 mils0.869″0.800″95 mils0.942″0.865″
600 kcmil68 mils0.955″0.885″65 mils0.955″0.880″95 mils10.040″0.965″