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Wire Gauge (AWG)

 

Common Wire Gauges

  • The common U.S. wire gauges (AWG) refers to the sizes of copper wire.  the resistivity of copper at 20 C is about \(\;\rho = 1.724 \;x\; 10^{-8} \; ohm / m \).
  • This table uses this value of resistivity, but it is known to vary by a few percentage points based on the purity and process of manufacturing.
AWG Wire Size (Solid)Diameter (in)Resistance per 1000 ft (ohms) Resistance per 1000 m (ohms)
24 0.0201 25.67 84.2
22 0.0254 16.14 52.7
20 0.0320  10.15  33.2
18 0.0403  6.385  20.9
16 0.0508 4.016 13.2
14 0.0640 2.525  8.28
12 0.0808 1.588 5.21
10 0.1019 0.999  3.28

Wire gauge is a measurement system used to determine the diameter or thickness of an electrical wire.  It indicates the size of the wire’s conductor, which directly affects how much electric current can safely carry without overheating.  The most common system used is the American Wire Gauge (AWG), where a smaller gauge number represents a thicker wire and a larger gauge number represents a thinner wire.  For example, a 10-gauge wire is thicker and can carry more current than a 20-gauge wire.  Wire gauge is an important factor in electrical and electronic applications because it affects resistance, current capacity, and voltage drop in a circuit.

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American Wire Gauge (AWG) and Resistances

  • The common U.S. wire gauges (AWG) refers to the sizes of copper wire.  the resistivity of copper at 20 C is about \(\;\rho = 1.724 \;x\; 10^{-8} \; ohm / m \).
  • This table uses this value of resistivity, but it is known to vary by a few percentage points based on the purity and process of manufacturing.
  • *  The AWG states areas of round copper wires in "circular mils", which is the square of the diameterin mils. \(\;1 \;mil = .001\; inch\).
  • **  Maximum current for chassis wiring.  The maximum current for power transmission is less.
AWG Wire Size (Solid)Area CM *Resistance per 1000 ft (ohms) @ 20 \(^\circ\)CDiameter (in)Maximum Current (amperes) **
0000 211600 0.049 0.46 380
000 167810 0.0618 0.40965 328
00 133080 0.078 0.3648 283
0 105530 0.0983 0.32485 245
1 83694 0.124 0.2893 211
2 66373 0.1563 0.25763 181
3 52634 0.197 0.22942 158
3 41742 0.2485 0.20431 135
4 41742 0.2485  0.20431 135
5 33102 0.3133 0.18194 118
6 26250 0.3951 0.16202 101
7 20816 0.4982 0.14428  89
8 16509 0.6282  0.12849 73
9 13094 0.7921 0.11443 64
10 10381 0.9989 0.10189 55 
11 8234 1.26 0.09074 47
12 6529 1.588 0.0808 41
13 5178.4 2.003 0.07196 35
14 4106.8 2.525 0.06408 32 
15 3256.7 3.184 0.05707 28
16 2582.9 4.016 0.05082 22
17 2048.2 5.064 0.o4526 19
18 1624.3 6.385 0.0403 16
19 1288.1 8.051 0.03589 14
20 1021.5 10.15 0.03196 11
21 810.1 12.8 0.02846 9
22 642.4 16.14 0.02535 7
23 509.45 20.36 0.02257 4.7
24 404.01 25.67 0.0201 3.5
25 320.4 32.37 0.0179 2.7
26 254.1   40.81 0.01594  2.2 
27 201.5  51.47  0.0142  1.7 
28 159.79  64.9  0.01264  1.4 
29 126.72  81.83  0.01126  1.2 
30 100.5  103.2  0.01002  0.86 
31 79.7  130.1  0.00893  0.7 
32 63.21  164.1  0.00795  0.53 
33 50.13  206.9  0.00708  0.43 
34 39.75  260.9  0.0063  0.33 
35 31.52  329  0.00561  0.27 
36 25  414.8  0.005  0.21 
37 19.83  523.1  0.00445  0.17 
38 15.72  659.6  0.00396   0.13
39  12.47 831.8  0.00353   0.11
40 9.89  1049  0.00314  0.09