American wire gauge (AWG), also known as the Brown & Sharpe wiregauge, is a standardized wire gauge system used since 1857 predominantly inNorth America for the diameters of round, solid, nonferrous, electricallyconducting wire. Dimensions of the wires are given in ASTM standard B 258. Thecrosssectional area of each gauge is an important factor for determining itscurrentcarrying capacity.
Increasing gauge numbers denote decreasing wire diameters, which issimilar to many other nonmetric gauging systems such as SWG. This gauge systemoriginated in the number of drawing operations used to produce a given gauge ofwire. Very fine wire (for example, 30 gauge) required more passes through thedrawing dies than 0 gauge wire did. Manufacturers of wire formerly hadproprietary wire gauge systems; the development of standardized wire gaugesrationalized selection of wire for a particular purpose.
The AWG tables are for a single, solid, round conductor. The AWG of astranded wire is determined by the crosssectional area of the equivalent solidconductor. Because there are also small gaps between the strands, a strandedwire will always have a slightly larger overall diameter than a solid wire withthe same AWG.
In the American Wire Gauge (AWG), diameters can be calculated by applyingthe formula:
D(AWG)=.005·92^{((36AWG)/39)} inch.
For the 00, 000, 0000 etc. gauges you use 1, 2, 3, which makes moresense mathematically than "double nought." This means that inAmerican wire gage every 6 gauge decrease gives a doubling of the wirediameter, and every 3 gauge decrease doubles the wire cross sectional area.Similar to dB in signal and power levels. An approximate but accurate enoughform of this formula contributed by Mario Rodriguez is:
D = .460 * (57/64)^{(awg +3)} or D = .460 * (0.890625)^{(awg+3)}.
Wire diameter calculations
The n gauge wire diameter d_{n} in inches (in) is equal to 0.005intimes 92 raised to the power of 36 minus gauge number n, divided by 39:
d_{n}_{ (in)} = 0.005 in × 92^{(36n)/39}
The n gauge wire diameter d_{n} in millimeters (mm) is equal to0.127mm times 92 raised to the power of 36 minus gauge number n, divided by 39:
d_{n}_{ (mm)} = 0.127 mm × 92^{(36n)/39}
Wire cross sectional area calculations
The n gauge wire's cross sercional area A_{n} in kilocircularmils (kcmil)is equal to 1000 times the square wire diameter d in inches (in):
A_{n}_{ (kcmil)} = 1000×d_{n}^{2}= 0.025 in^{2}× 92^{(36n)/19.5}
The n gauge wire's cross sercional area A_{n} in square inches (in^{2})isequal to pi divided by 4 times the square wire diameter d in inches (in):
A_{n}_{ (in}2_{)} = (π/4)×d_{n}^{2}=0.000019635 in^{2} × 92^{(36n)/19.5}
The n gauge wire's cross sercional area A_{n}in square millimeters(mm^{2})is equal to pi divided by 4 times the square wire diameter d inmillimeters (mm):
A_{n}_{ (mm}2_{)} = (π/4)×d_{n}^{2}=0.012668 mm^{2} × 92^{(36n)/19.5}
Wire resistance calculations
The n gauge wire resistance R in ohms per kilofeet (Ω/kft) is equal to0.3048×1000000000 times the wire's resistivity ρ inohmmeters (Ω·m)divided by 25.4^{2} times the cross sectional area A_{n}in square inches (in^{2}):
R_{n }_{(Ω/kft)} = 0.3048 × 10^{9} × ρ_{(Ω·m)} /(25.4^{2}× A_{n}_{ (in}2_{)})
The n gauge wire resistance R in ohms per kilometer (Ω/km) is equal to1000000000 times the wire's resistivity ρ inohmmeters (Ω·m) divided bythe cross sectional area A_{n} in square millimeters (mm^{2}):
R_{n }_{(Ω/km)} = 10^{9}× ρ_{(Ω·m)} / A_{n}_{(mm}2_{)}
American wire gauge (AWG), also known as the Brown & Sharpe wiregauge, is a standardized wire gauge system used since 1857 predominantly inNorth America for the diameters of round, solid, nonferrous, electricallyconducting wire. Dimensions of the wires are given in ASTM standard B 258. Thecrosssectional area of each gauge is an important factor for determining itscurrentcarrying capacity.
Increasing gauge numbers denote decreasing wire diameters, which issimilar to many other nonmetric gauging systems such as SWG. This gauge systemoriginated in the number of drawing operations used to produce a given gauge ofwire. Very fine wire (for example, 30 gauge) required more passes through thedrawing dies than 0 gauge wire did. Manufacturers of wire formerly hadproprietary wire gauge systems; the development of standardized wire gaugesrationalized selection of wire for a particular purpose.
The AWG tables are for a single, solid, round conductor. The AWG of astranded wire is determined by the crosssectional area of the equivalent solidconductor. Because there are also small gaps between the strands, a strandedwire will always have a slightly larger overall diameter than a solid wire withthe same AWG.
In the American Wire Gauge (AWG), diameters can be calculated by applyingthe formula:
D(AWG)=.005·92^{((36AWG)/39)} inch.
For the 00, 000, 0000 etc. gauges you use 1, 2, 3, which makes moresense mathematically than "double nought." This means that inAmerican wire gage every 6 gauge decrease gives a doubling of the wirediameter, and every 3 gauge decrease doubles the wire cross sectional area.Similar to dB in signal and power levels. An approximate but accurate enoughform of this formula contributed by Mario Rodriguez is:
D = .460 * (57/64)^{(awg +3)} or D = .460 * (0.890625)^{(awg+3)}.
Wire diameter calculations
The n gauge wire diameter d_{n} in inches (in) is equal to 0.005intimes 92 raised to the power of 36 minus gauge number n, divided by 39:
d_{n}_{ (in)} = 0.005 in × 92^{(36n)/39}
The n gauge wire diameter d_{n} in millimeters (mm) is equal to0.127mm times 92 raised to the power of 36 minus gauge number n, divided by 39:
d_{n}_{ (mm)} = 0.127 mm × 92^{(36n)/39}
Wire cross sectional area calculations
The n gauge wire's cross sercional area A_{n} in kilocircularmils (kcmil)is equal to 1000 times the square wire diameter d in inches (in):
A_{n}_{ (kcmil)} = 1000×d_{n}^{2}= 0.025 in^{2}× 92^{(36n)/19.5}
The n gauge wire's cross sercional area A_{n} in square inches (in^{2})isequal to pi divided by 4 times the square wire diameter d in inches (in):
A_{n}_{ (in}2_{)} = (π/4)×d_{n}^{2}=0.000019635 in^{2} × 92^{(36n)/19.5}
The n gauge wire's cross sercional area A_{n}in square millimeters(mm^{2})is equal to pi divided by 4 times the square wire diameter d inmillimeters (mm):
A_{n}_{ (mm}2_{)} = (π/4)×d_{n}^{2}=0.012668 mm^{2} × 92^{(36n)/19.5}
Wire resistance calculations
The n gauge wire resistance R in ohms per kilofeet (Ω/kft) is equal to0.3048×1000000000 times the wire's resistivity ρ inohmmeters (Ω·m)divided by 25.4^{2} times the cross sectional area A_{n}in square inches (in^{2}):
R_{n }_{(Ω/kft)} = 0.3048 × 10^{9} × ρ_{(Ω·m)} /(25.4^{2}× A_{n}_{ (in}2_{)})
The n gauge wire resistance R in ohms per kilometer (Ω/km) is equal to1000000000 times the wire's resistivity ρ inohmmeters (Ω·m) divided bythe cross sectional area A_{n} in square millimeters (mm^{2}):
R_{n }_{(Ω/km)} = 10^{9}× ρ_{(Ω·m)} / A_{n}_{(mm}2_{)}
Tables of AWG wire sizes 

Wire Size 
SWG 
AWG 
BWG 

Inch 
MM 
SQMM 
Inch 
MM 
SQMM 
Inch 
MM 
SQMM 

4/0 
0.4 
10.16 
81.073 
0.46 
11.68 
107.145 
0.454 
11.53 
104.411 
3/0 
0.372 
9.45 
70.138 
0.409 
10.41 
85.112 
0.425 
10.8 
91.608 
2/0 
0.348 
8.84 
61.375 
0.365 
9.27 
67.491 
0.38 
9.65 
73.138 
1/0 
0.324 
8.23 
53.197 
0.325 
8.25 
53.456 
0.34 
8.64 
58.629 
1 
0.3 
7.62 
45.603 
0.289 
7.35 
42.429 
0.3 
7.62 
45.603 
2 
0.276 
7.01 
38.594 
0.258 
6.54 
33.592 
0.283 
7.21 
40.828 
3 
0.252 
6.4 
32.169 
0.229 
5.83 
26.694 
0.259 
6.58 
34.004 
4 
0.232 
5.89 
27.247 
0.204 
5.19 
21.155 
0.238 
6.05 
28.747 
5 
0.212 
5.38 
22.732 
0.182 
4.62 
16.763 
0.22 
5.59 
24.542 
6 
0.192 
4.88 
18.703 
0.162 
4.11 
13.267 
0.203 
5.16 
20.911 
7 
0.176 
4.47 
15.692 
0.144 
3.66 
10.52 
0.179 
4.57 
16.402 
8 
0.16 
4.06 
12.946 
0.128 
3.26 
8.346 
0.164 
4.19 
13.788 
9 
0.144 
3.66 
10.52 
0.114 
2.9 
6.605 
0.147 
3.76 
11.103 
10 
0.128 
3.25 
8.295 
0.102 
2.59 
5.268 
0.134 
3.4 
9.079 
11 
0.116 
2.95 
6.834 
0.091 
2.3 
4.154 
0.12 
3.05 
7.306 
12 
0.104 
2.64 
5.473 
0.081 
2.05 
3.3 
0.109 
2.77 
6.026 
13 
0.092 
2.34 
4.3 
0.072 
1.83 
2.63 
0.095 
2.41 
4.561 
14 
0.081 
2.03 
3.236 
0.064 
1.63 
2.086 
0.083 
2.11 
3.496 
15 
0.072 
1.83 
2.63 
0.057 
1.45 
1.651 
0.072 
1.83 
2.63 
16 
0.064 
1.63 
2.086 
0.051 
1.29 
1.306 
0.065 
1.65 
2.086 
17 
0.056 
1.42 
1.583 
0.045 
1.15 
1.038 
0.058 
1.47 
1.697 
18 
0.048 
1.22 
1.168 
0.04 
1.02 
0.817 
0.049 
1.24 
1.207 
19 
0.04 
1.02 
0.817 
0.036 
0.91 
0.65 
0.042 
1.07 
0.899 
20 
0.036 
0.92 
0.664 
0.032 
0.81 
0.515 
0.035 
0.89 
0.58 
21 
0.032 
0.81 
0.515 
0.028 
0.72 
0.407 
0.031 
0.81 
0.515 
22 
0.028 
0.71 
0.395 
0.025 
0.64 
0.321 
0.028 
0.71 
0.395 
23 
0.024 
0.61 
0.292 
0.023 
0.57 
0.255 
0.025 
0.64 
0.321 
24 
0.023 
0.56 
0.246 
0.02 
0.51 
0.204 
0.023 
0.56 
0.246 
25 
0.02 
0.51 
0.204 
0.018 
0.45 
0.159 
0.02 
0.51 
0.204 
26 
0.018 
0.46 
0.166 
0.016 
0.4 
0.125 
0.018 
0.46 
0.166 
27 
0.016 
0.41 
0.132 
0.014 
0.36 
0.101 
0.016 
0.41 
0.132 
28 
0.014 
0.38 
0.101 
0.013 
0.32 
0.08 
0.0135 
0.356 
0.995 
29 
0.013 
0.35 
0.096 
0.011 
0.29 
0.066 
0.013 
0.33 
0.855 
30 
0.012 
0.305 
0.073 
0.01 
0.25 
0.049 
0.012 
0.305 
0.073 
31 
0.011 
0.29 
0.066 
0.09 
0.229 
0.041 
0.01 
0.254 
0.05 
32 
0.0106 
0.27 
0.057 
0.008 
0.203 
0.032 
0.009 
0.229 
0.041 
33 
0.01 
0.254 
0.05 
0.007 
0.178 
0.024 
0.008 
0.203 
0.032 
34 
0.009 
0.229 
0.041 
0.0063 
0.16 
0.02 
0.007 
0.178 
0.024 
35 
0.008 
0.203 
0.032 
0.0056 
0.14 
0.015 
0.005 
0.127 
0.012 
36 
0.007 
0.178 
0.024 
0.005 
0.127 
0.012 
0.004 
0.102 
0.008 
37 
0.0067 
0.17 
0.022 
0.0044 
0.11 
0.009 

38 
0.006 
0.15 
0.017 
0.004 
0.102 
0.008 

39 
0.005 
0.127 
0.012 
0.0035 
0.09 
0.006 

40 
0.0047 
0.12 
0.011 
0.0031 
0.08 
0.005 
American Wire Gauge (AWG) Cable / Conductor Sizes and Properties 

AWG 
Diameter 
Diameter 
Area 
Resistance 
Resistance 
Max Current 
Max Frequency 
[inches] 
[mm] 
[mm^{2}] 
[Ohms / 1000 ft] 
[Ohms / km] 
[Amperes] 
for 100% skin depth 

0000 (4/0) 
0.46 
11.684 
107 
0.049 
0.16072 
302 
125 Hz 
000 (3/0) 
0.4096 
10.40384 
85 
0.0618 
0.202704 
239 
160 Hz 
00 (2/0) 
0.3648 
9.26592 
67.4 
0.0779 
0.255512 
190 
200 Hz 
0 (1/0) 
0.3249 
8.25246 
53.5 
0.0983 
0.322424 
150 
250 Hz 
1 
0.2893 
7.34822 
42.4 
0.1239 
0.406392 
119 
325 Hz 
2 
0.2576 
6.54304 
33.6 
0.1563 
0.512664 
94 
410 Hz 
3 
0.2294 
5.82676 
26.7 
0.197 
0.64616 
75 
500 Hz 
4 
0.2043 
5.18922 
21.2 
0.2485 
0.81508 
60 
650 Hz 
5 
0.1819 
4.62026 
16.8 
0.3133 
1.027624 
47 
810 Hz 
6 
0.162 
4.1148 
13.3 
0.3951 
1.295928 
37 
1100 Hz 
7 
0.1443 
3.66522 
10.5 
0.4982 
1.634096 
30 
1300 Hz 
8 
0.1285 
3.2639 
8.37 
0.6282 
2.060496 
24 
1650 Hz 
9 
0.1144 
2.90576 
6.63 
0.7921 
2.598088 
19 
2050 Hz 
10 
0.1019 
2.58826 
5.26 
0.9989 
3.276392 
15 
2600 Hz 
11 
0.0907 
2.30378 
4.17 
1.26 
4.1328 
12 
3200 Hz 
12 
0.0808 
2.05232 
3.31 
1.588 
5.20864 
9.3 
4150 Hz 
13 
0.072 
1.8288 
2.62 
2.003 
6.56984 
7.4 
5300 Hz 
14 
0.0641 
1.62814 
2.08 
2.525 
8.282 
5.9 
6700 Hz 
15 
0.0571 
1.45034 
1.65 
3.184 
10.44352 
4.7 
8250 Hz 
16 
0.0508 
1.29032 
1.31 
4.016 
13.17248 
3.7 
11 k Hz 
17 
0.0453 
1.15062 
1.04 
5.064 
16.60992 
2.9 
13 k Hz 
18 
0.0403 
1.02362 
0.823 
6.385 
20.9428 
2.3 
17 kHz 
19 
0.0359 
0.91186 
0.653 
8.051 
26.40728 
1.8 
21 kHz 
20 
0.032 
0.8128 
0.518 
10.15 
33.292 
1.5 
27 kHz 
21 
0.0285 
0.7239 
0.41 
12.8 
41.984 
1.2 
33 kHz 
22 
0.0254 
0.64516 
0.326 
16.14 
52.9392 
0.92 
42 kHz 
23 
0.0226 
0.57404 
0.258 
20.36 
66.7808 
0.729 
53 kHz 
24 
0.0201 
0.51054 
0.205 
25.67 
84.1976 
0.577 
68 kHz 
25 
0.0179 
0.45466 
0.162 
32.37 
106.1736 
0.457 
85 kHz 
26 
0.0159 
0.40386 
0.129 
40.81 
133.8568 
0.361 
107 kHz 
27 
0.0142 
0.36068 
0.102 
51.47 
168.8216 
0.288 
130 kHz 
28 
0.0126 
0.32004 
0.081 
64.9 
212.872 
0.226 
170 kHz 
29 
0.0113 
0.28702 
0.0642 
81.83 
268.4024 
0.182 
210 kHz 
30 
0.01 
0.254 
0.0509 
103.2 
338.496 
0.142 
270 kHz 
31 
0.0089 
0.22606 
0.0404 
130.1 
426.728 
0.113 
340 kHz 
32 
0.008 
0.2032 
0.032 
164.1 
538.248 
0.091 
430 kHz 
33 
0.0071 
0.18034 
0.0254 
206.9 
678.632 
0.072 
540 kHz 
34 
0.0063 
0.16002 
0.0201 
260.9 
855.752 
0.056 
690 kHz 
35 
0.0056 
0.14224 
0.016 
329 
1079.12 
0.044 
870 kHz 
36 
0.005 
0.127 
0.0127 
414.8 
1360 
0.035 
1100 kHz 
37 
0.0045 
0.1143 
0.01 
523.1 
1715 
0.0289 
1350 kHz 
38 
0.004 
0.1016 
0.00797 
659.6 
2163 
0.0228 
1750 kHz 
39 
0.0035 
0.0889 
0.00632 
831.8 
2728 
0.0175 
2250 kHz 
40 
0.0031 
0.07874 
0.00501 
1049 
3440 
0.0137 
2900 kHz 
AWG Notes: American WireGauge (AWG) is a standardized wire gauge system used predominantly in theUnited States to note the diameter of electrically conducting wire.The generalrule of thumb is for every 6 gauge decrease the wire diameter doubles and every3 gauge decrease doubles the cross sectional area.
Diameter Notes: A mil is a unitof length equal to 0.001 inch (a "milliinch" or a "thousandthof one inch")ie. 1 mil = 0.001".
Resistance Notes: The resistancenoted in the table above is for copper wire conductor.For a given current, youcan use the noted resistance and apply Ohms Law to calculate the voltage dropacross the conductor.
Current (ampacity) Notes: Thecurrent ratings shown in the table are for power transmission and have beendetermined using the rule of1 amp per 700 circular mils, which is a veryconservative rating.For reference, the National Electrical Code (NEC) notesthe following ampacity for copper wire at 30 Celsius:
14 AWG  maximum of 20 Amps in free air, maximum of 15 Amps as part of a 3conductor cable;
12 AWG  maximum of 25 Amps in free air, maximum of 20 Amps as part of a 3conductor cable;
10 AWG  maximum of 40 Amps in free air, maximum of 30 Amps as part of a 3conductor cable.
Check your local electrical code for the correct current capacity (ampacity)for mains and in wall wiring.
Skin Effect and Skin Depth Notes: Skin effect is the tendency of an alternating electric current (AC) todistribute itself within a conductor so that the current density near thesurface of the conductor is greater than that at its core. That is, theelectric current tends to flow at the "skin" of the conductor. Theskin effect causes the effective resistance of the conductor to increase withthe frequency of the current.Themaximum frequency show is for 100% skin depth(ie. no skin effects).
AWG Notes: American WireGauge (AWG) is a standardized wire gauge system used predominantly in theUnited States to note the diameter of electrically conducting wire.The generalrule of thumb is for every 6 gauge decrease the wire diameter doubles and every3 gauge decrease doubles the cross sectional area.
Diameter Notes: A mil is a unitof length equal to 0.001 inch (a "milliinch" or a "thousandthof one inch")ie. 1 mil = 0.001".
Resistance Notes: The resistancenoted in the table above is for copper wire conductor.For a given current, youcan use the noted resistance and apply Ohms Law to calculate the voltage dropacross the conductor.
Current (ampacity) Notes: Thecurrent ratings shown in the table are for power transmission and have beendetermined using the rule of1 amp per 700 circular mils, which is a veryconservative rating.For reference, the National Electrical Code (NEC) notesthe following ampacity for copper wire at 30 Celsius:
14 AWG  maximum of 20 Amps in free air, maximum of 15 Amps as part of a 3conductor cable;
12 AWG  maximum of 25 Amps in free air, maximum of 20 Amps as part of a 3conductor cable;
10 AWG  maximum of 40 Amps in free air, maximum of 30 Amps as part of a 3conductor cable.
Check your local electrical code for the correct current capacity (ampacity)for mains and in wall wiring.
Skin Effect and Skin Depth Notes: Skin effect is the tendency of an alternating electric current (AC) todistribute itself within a conductor so that the current density near thesurface of the conductor is greater than that at its core. That is, theelectric current tends to flow at the "skin" of the conductor. The skineffect causes the effective resistance of the conductor to increase with thefrequency of the current.Themaximum frequency show is for 100% skin depth (ie.no skin effects).