Build my own cabin - DIY projects

NEC 2002: Chapter 9 Table 4

 

Dimensions and Percent Area of Conduit and Tubing (See Chapter 9 Table 1 for allowed use of conduit area)
Article 358 - Electrical Metallic Tubing (EMT)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
16 1⁄2 15.8 0.622 196 0.304 118 0.182 104 0.161 61 0.094 78 0.122
21 3⁄4 20.9 0.824 343 0.533 206 0.32 182 0.283 106 0.165 137 0.213
27 1 26.6 1.049 556 0.864 333 0.519 295 0.458 172 0.268 222 0.346
35 1 1⁄4 35.1 1.38 968 1.496 581 0.897 513 0.793 300 0.464 387 0.598
41 1 1⁄2 40.9 1.61 1314 2.036 788 1.221 696 1.079 407 0.631 526 0.814
53 2 52.5 2.067 2165 3.356 1299 2.013 1147 1.778 671 1.04 866 1.342
63 2 1⁄2 69.4 2.731 3783 5.858 2270 3.515 2005 3.105 1173 1.816 1513 2.343
78 3 85.2 3.356 5701 8.846 3421 5.307 3022 4.688 1767 2.742 2280 3.538
91 3 1⁄2 97.4 3.834 7451 11.545 4471 6.927 3949 6.119 2310 3.579 2980 4.618
103 4 110.1 4.334 9521 14.753 5712 8.852 5046 7.819 2951 4.573 3808 5.901
Article 362 - Electrical Nonmetallic Tubing (ENT)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
16 1⁄2 14.2 0.56 158 0.246 95 0.148 84 0.131 49 0.076 63 0.099
21 3⁄4 19.3 0.76 293 0.454 176 0.272 155 0.24 91 0.141 117 0.181
27 1 25.4 1 507 0.785 304 0.471 269 0.416 157 0.243 203 0.314
35 1 1⁄4 34 1.34 908 1.41 545 0.846 481 0.747 281 0.437 363 0.564
41 1 1⁄2 39.9 1.57 1250 1.936 750 1.162 663 1.026 388 0.6 500 0.774
53 2 51.3 2.02 2067 3.205 1240 1.923 1095 1.699 641 0.993 827 1.282
63 2 1⁄2
78 3
91 3 1⁄2
Article 348 - Flexible Metal Conduit (FMC)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
12 3⁄8 9.7 0.384 74 0.116 44 0.069 39 0.061 23 0.036 30 0.046
16 1⁄2 16.1 0.635 204 0.317 122 0.19 108 0.168 63 0.098 81 0.127
21 3⁄4 20.9 0.824 343 0.533 206 0.32 182 0.283 106 0.165 137 0.213
27 1 25.9 1.02 527 0.817 316 0.49 279 0.433 163 0.253 211 0.327
35 1 1⁄4 32.4 1.275 824 1.277 495 0.766 437 0.677 256 0.396 330 0.511
41 1 1⁄2 39.1 1.538 1201 1.858 720 1.115 636 0.985 372 0.576 480 0.743
53 2 51.8 2.04 2107 3.269 1264 1.961 1117 1.732 653 1.013 843 1.307
63 2 1⁄2 63.5 2.5 3167 4.909 1900 2.945 1678 2.602 982 1.522 1267 1.963
78 3 76.2 3 4560 7.069 2736 4.241 2417 3.746 1414 2.191 1824 2.827
91 3 1⁄2 88.9 3.5 6207 9.621 3724 5.773 3290 5.099 1924 2.983 2483 3.848
103 4 101.6 4 8107 12.566 4864 7.54 4297 6.66 2513 3.896 3243 5.027
Article 324 - Intermediate Metal Conduit (IMC)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
12 3⁄8
16 1⁄2 16.8 0.66 222 0.342 133 0.205 117 0.181 69 0.106 89 0.137
21 3⁄4 21.9 0.864 377 0.586 226 0.352 200 0.311 117 0.182 151 0.235
27 1 28.1 1.105 620 0.959 372 0.575 329 0.508 192 0.297 248 0.384
35 1 1⁄4 36.8 1.448 1064 1.647 638 0.988 564 0.873 330 0.51 425 0.659
41 1 1⁄2 42.7 1.683 1432 2.225 859 1.335 759 1.179 444 0.69 573 0.89
53 2 54.6 2.15 2341 3.63 1405 2.178 1241 1.924 726 1.125 937 1.452
63 2 1⁄2 64.9 2.557 3308 5.135 1985 3.081 1753 2.722 1026 1.592 1323 2.054
78 3 80.7 3.176 5115 7.922 3069 4.753 2711 4.199 1586 2.456 2046 3.169
91 3 1⁄2 93.2 3.671 6822 10.584 4093 6.351 3616 5.61 2115 3.281 2729 4.234
103 4 105.4 4.166 8725 13.631 5235 8.179 4624 7.224 2705 4.226 3490 5.452
Article 356 - Liquidtight Flexible Nonmetalic Conduit (LFNC-B)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
12 3⁄8 12.5 0.494 123 0.192 74 0.115 65 0.102 38 0.059 49 0.077
16 1⁄2 16.1 0.632 204 0.314 122 0.188 108 0.166 63 0.097 81 0.125
21 3⁄4 21.1 0.83 350 0.541 210 0.325 185 0.287 108 0.168 140 0.216
27 1 26.8 1.054 564 0.873 338 0.524 299 0.462 175 0.27 226 0.349
35 1 1⁄4 35.4 1.395 984 1.528 591 0.917 522 0.81 305 0.474 394 0.611
41 1 1⁄2 40.3 1.588 1276 1.981 765 1.188 676 1.05 395 0.614 510 0.792
53 2 51.6 2.033 2091 3.246 1255 1.948 1108 1.72 648 1.006 836 1.298
Article 356 - Liquidtight Flexible Nonmetalic Conduit (LFNC-A)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
12 3⁄8 12.6 0.495 125 0.192 75 0.115 66 0.102 39 0.06 50 0.077
16 1⁄2 16 0.63 201 0.312 121 0.187 107 0.165 62 0.097 80 0.125
21 3⁄4 21 0.825 346 0.535 208 0.321 184 0.283 107 0.166 139 0.214
27 1 26.5 1.043 552 0.854 331 0.513 292 0.453 171 0.265 221 0.342
35 11⁄4 35.1 1.383 968 1.502 581 0.901 513 0.796 300 0.466 387 0.601
41 11⁄2 40.7 1.603 1301 2.018 781 1.211 690 1.07 403 0.626 520 0.807
53 2 52.4 2.063 2157 3.343 1294 2.006 1143 1.772 669 1.036 863 1.337
Article 350 - Liquidtight Flexible Metal Conduit (LFMC)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
12 3⁄8 12.5 0.494 123 0.192 74 0.115 65 0.102 38 0.059 49 0.077
16 1⁄2 16.1 0.632 204 0.314 122 0.188 108 0.166 63 0.097 81 0.125
21 3⁄4 21.1 0.83 350 0.541 210 0.325 185 0.287 108 0.168 140 0.216
27 1 26.8 1.054 564 0.873 338 0.524 299 0.462 175 0.27 226 0.349
35 1 1⁄4 35.4 1.395 984 1.528 591 0.917 522 0.81 305 0.474 394 0.611
41 1 1⁄2 40.3 1.588 1276 1.981 765 1.188 676 1.05 395 0.614 510 0.792
53 2 51.6 2.033 2091 3.246 1255 1.948 1108 1.72 648 1.006 836 1.298
63 2 1⁄2 63.3 2.493 3147 4.881 1888 2.929 1668 2.587 976 1.513 1259 1.953
78 3 78.4 3.085 4827 7.475 2896 4.485 2559 3.962 1497 2.317 1931 2.99
91 3 1⁄2 89.4 3.52 6277 9.731 3766 5.839 3327 5.158 1946 3.017 2511 3.893
103 4 102.1 4.02 8187 12.692 4912 7.615 4339 6.727 2538 3.935 3275 5.077
129 5
155 6
Article 344 - Rigid Metal Conduit (RMC)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
12 3⁄8
16 1⁄2 16.1 0.632 204 0.314 122 0.188 108 0.166 63 0.097 81 0.125
21 3⁄4 21.2 0.836 353 0.549 212 0.329 187 0.291 109 0.17 141 0.22
27 1 27 1.063 573 0.887 344 0.532 303 0.47 177 0.275 229 0.355
35 1 1⁄4 35.4 1.394 984 1.526 591 0.916 522 0.809 305 0.473 394 0.61
41 1 1⁄2 41.2 1.624 1333 2.071 800 1.243 707 1.098 413 0.642 533 0.829
53 2 52.9 2.083 2198 3.408 1319 2.045 1165 1.806 681 1.056 879 1.363
63 2 1⁄2 63.2 2.489 3137 4.866 1882 2.919 1663 2.579 972 1.508 1255 1.946
78 3 78.5 3.09 4840 7.499 2904 4.499 2565 3.974 1500 2.325 1936 3
91 3 1⁄2 90.7 3.57 6461 10.01 3877 6.006 3424 5.305 2003 3.103 2584 4.004
103 4 102.9 4.05 8316 12.882 4990 7.729 4408 6.828 2578 3.994 3326 5.153
129 5 128.9 5.073 13050 20.212 7830 12.127 6916 10.713 4045 6.266 5220 8.085
155 6 154.8 6.093 18821 29.158 11292 17.495 9975 15.454 5834 9.039 7528 11.663
Article 352 - Rigid PVC Conduit (PVC), Schedule 80
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
12 3⁄8
16 1⁄2 13.4 0.526 141 0.217 85 0.13 75 0.115 44 0.067 56 0.087
21 3⁄4 18.3 0.722 263 0.409 158 0.246 139 0.217 82 0.127 105 0.164
27 1 23.8 0.936 445 0.688 267 0.413 236 0.365 138 0.213 178 0.275
35 1 1⁄4 31.9 1.255 799 1.237 480 0.742 424 0.656 248 0.383 320 0.495
41 1 1⁄2 37.5 1.476 1104 1.711 663 1.027 585 0.907 342 0.53 442 0.684
53 2 48.6 1.913 1855 2.874 1113 1.725 983 1.523 575 0.891 742 1.15
63 2 1⁄2 58.2 2.29 2660 4.119 1596 2.471 1410 2.183 825 1.277 1064 1.647
78 3 72.7 2.864 4151 6.442 2491 3.865 2200 3.414 1287 1.997 1660 2.577
91 3 1⁄2 84.5 3.326 5608 8.688 3365 5.213 2972 4.605 1738 2.693 2243 3.475
103 4 96.2 3.786 7268 11.258 4361 6.755 3852 5.967 2253 3.49 2907 4.503
129 5 121.1 4.768 11518 17.855 6911 10.713 6105 9.463 3571 5.535 4607 7.142
155 6 145 5.709 16513 25.598 9908 15.359 8752 13.567 5119 7.935 6605 10.239
Articles 352 and 353 - Rigid PVC Conduit (PVC), Schedule 40, and HDPE Conduit (HDPE)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
12 3⁄8
16 1⁄2 15.3 0.602 184 0.285 110 0.171 97 0.151 57 0.088 74 0.114
21 3⁄4 20.4 0.804 327 0.508 196 0.305 173 0.269 101 0.157 131 0.203
27 1 26.1 1.029 535 0.832 321 0.499 284 0.441 166 0.258 214 0.333
35 1 1⁄4 34.5 1.36 935 1.453 561 0.872 495 0.77 290 0.45 374 0.581
41 1 1⁄2 40.4 1.59 1282 1.986 769 1.191 679 1.052 397 0.616 513 0.794
53 2 52 2.047 2124 3.291 1274 1.975 1126 1.744 658 1.02 849 1.316
63 2 1⁄2 62.1 2.445 3029 4.695 1817 2.817 1605 2.488 939 1.455 1212 1.878
78 3 77.3 3.042 4693 7.268 2816 4.361 2487 3.852 1455 2.253 1877 2.907
91 3 1⁄2 89.4 3.521 6277 9.737 3766 5.842 3327 5.161 1946 3.018 2511 3.895
103 4 101.5 3.998 8091 12.554 4855 7.532 4288 6.654 2508 3.892 3237 5.022
129 5 127.4 5.016 12748 19.761 7649 11.856 6756 10.473 3952 6.126 5099 7.904
155 6 153.2 6.031 18433 28.567 11060 17.14 9770 15.141 5714 8.856 7373 11.427
Article 352 - Type A, Rigid PVC Conduit (PVC)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
16 1⁄2 17.8 0.7 249 0.385 149 0.231 132 0.204 77 0.119 100 0.154
21 3⁄4 23.1 0.91 419 0.65 251 0.39 222 0.345 130 0.202 168 0.26
27 1 29.8 1.175 697 1.084 418 0.651 370 0.575 216 0.336 279 0.434
35 1 1⁄4 38.1 1.5 1140 1.767 684 1.06 604 0.937 353 0.548 456 0.707
41 1 1⁄2 43.7 1.72 1500 2.324 900 1.394 795 1.231 465 0.72 600 0.929
53 2 54.7 2.155 2350 3.647 1410 2.188 1245 1.933 728 1.131 940 1.459
63 2 1⁄2 66.9 2.635 3515 5.453 2109 3.272 1863 2.89 1090 1.69 1406 2.181
78 3 82 3.23 5281 8.194 3169 4.916 2799 4.343 1637 2.54 2112 3.278
91 3 1⁄2 93.7 3.69 6896 10.694 4137 6.416 3655 5.668 2138 3.315 2758 4.278
103 4 106.2 4.18 8858 13.723 5315 8.234 4695 7.273 2746 4.254 3543 5.489
129 5
155 6
Article 352 - Type EB, Rigid PVC Conduit (PVC)
Metric Designator Trade Size Nominal Internal Diameter Total Area 100% 60% 1 Wire
53%
2 Wires
31%
Over 2 Wires
40%
mm in. mm² in.² mm² in.² mm² in.² mm² in.² mm² in.²
16 1⁄2
21 3⁄4
27 1
35 1 1⁄4
41 1 1⁄2
53 2 56.4 2.221 2498 3.874 1499 2.325 1324 2.053 774 1.201 999 1.55
63 2 1⁄2
78 3 84.6 3.33 5621 8.709 3373 5.226 2979 4.616 1743 2.7 2248 3.484
91 3 1⁄2 96.6 3.804 7329 11.365 4397 6.819 3884 6.023 2272 3.523 2932 4.546
103 4 108.9 4.289 9314 14.448 5589 8.669 4937 7.657 2887 4.479 3726 5.779
129 5 135 5.316 14314 22.195 8588 13.317 7586 11.763 4437 6.881 5726 8.878
155 6 160.9 6.336 20333 31.53 12200 18.918 10776 16.711 6303 9.774 8133 12.612

Back to Index of NEC Tables

Click the icons below to get our NEC® compliant Electrical Calc Elite or Electric Toolkit for Android and iOS.  The Electrical Calc Elite is designed to solve many of your common code-based electrical calculations like wire sizes, voltage drop, conduit sizing, etc.  The Electric Toolkit provides some basic electrical calculations, wiring diagrams (similar to those found on this website), and other electrical reference data. 

      Electrical Calc Elite    electric-toolkit-android