Wire resistance

The resistance of a wire is determined by the material, length and cross-section of the wire. You can calculate the resistance of a wire with the calculator below or calculate it yourself with the formulas.

Formulas

R is the symbol for resistance and is measured in ohm (Ω).
A is the symbol for area and is measured in square meters (m 2 ).
ρ is the symbol for resistivity and is measured in ohm-meter (Ω⋅m).
l is the symbol for length and is measured in meter (m).

Calculator

Enter three values to calculate the remaining one.

material resistivity ρ 10⁻⁹Ω⋅m
silver 15.9
copper 16.8
aluminium 26.5
tungsten 56
iron 97.1
platinum 106
manganin 482
mercury 980
nichrome 1000
constantan 490
AWG diameter (inch) diameter (mm) area (kcmil) area (mm 2 )
0000 (4/0) 0.46 11.684 211.6 107.219
000 (3/0) 0.40964 10.4049 167.806 85.0288
00 (2/0) 0.3648 9.26583 133.077 67.4309
0 (1/0) 0.32486 8.25146 105.534 53.4751
1 0.2893 7.34814 83.6927 42.4077
2 0.25763 6.54371 66.3713 33.6308
3 0.22942 5.82734 52.6348 26.6705
4 0.20431 5.1894 41.7413 21.1506
5 0.18194 4.62129 33.1024 16.7732
6 0.16202 4.11538 26.2514 13.3018
7 0.14429 3.66485 20.8183 10.5488
8 0.12849 3.26364 16.5097 8.36556
9 0.11442 2.90636 13.0928 6.63419
10 0.1019 2.58819 10.383 5.26115
11 0.09074 2.30485 8.23411 4.17229
12 0.08081 2.05253 6.52995 3.30877
13 0.07196 1.82783 5.17848 2.62398
14 0.06408 1.62773 4.10672 2.08091
15 0.05707 1.44953 3.25678 1.65023
16 0.05082 1.29085 2.58274 1.3087
17 0.04526 1.14953 2.04821 1.03784
18 0.0403 1.02369 1.6243 0.82305
19 0.03589 0.91162 1.28813 0.65271
20 0.03196 0.81182 1.02153 0.51762
21 0.02846 0.72295 0.81011 0.41049
22 0.02535 0.6438 0.64245 0.32553
23 0.02257 0.57332 0.50949 0.25816
24 0.0201 0.51056 0.40404 0.20473
25 0.0179 0.45467 0.32042 0.16236
26 0.01594 0.40489 0.2541 0.12876
27 0.0142 0.36057 0.20151 0.10211
28 0.01264 0.32109 0.15981 0.08098
29 0.01126 0.28594 0.12673 0.06422
30 0.01003 0.25464 0.1005 0.05093
31 0.00893 0.22676 0.0797 0.04039
32 0.00795 0.20194 0.06321 0.03203
33 0.00708 0.17983 0.05013 0.0254
34 0.0063 0.16014 0.03975 0.02014
35 0.00561 0.14261 0.03152 0.01597
36 0.005 0.127 0.025 0.01267
37 0.00445 0.1131 0.01983 0.01005
38 0.00397 0.10072 0.01572 0.00797
39 0.00353 0.08969 0.01247 0.00632
40 0.00314 0.07987 0.00989 0.00501