American Wire Guage Sizes

The American Wire Gauge (AWG), diameters can be calculated by applying the formula:

 D(AWG) = 0.005 inch X 92((36-AWG)/39)

For the 1/0, 2/0, 3/0, 4/0 gauges you use 0, -1, -2, -3, respectively. This makes more mathematical sense than "double nought."

In American wire gauge every 6 gauge decrease gives a doubling of the wire diameter, and every 3 gauge decrease doubles the wire cross sectional area.  

AWG

Diameter

Turns of wire

Area

Copper
resistance

(inch)

(mm)

(per inch)

(per cm)

(kcmil)

(mm²)

(Ω/km)

(Ω/kFT)

 (4/0)

0.4600

11.684

2.17

0.856

212

107

0.1608

0.04901

 (3/0)

0.4096

10.404

2.44

0.961

168

85.0

0.2028

0.06180

 (2/0)

0.3648

9.266

2.74

1.08

133

67.4

0.2557

0.07793

 (1/0)

0.3249

8.252

3.08

1.21

106

53.5

0.3224

0.09827

1

0.2893

7.348

3.46

1.36

83.7

42.4

0.4066

0.1239

2

0.2576

6.544

3.88

1.53

66.4

33.6

0.5127

0.1563

3

0.2294

5.827

4.36

1.72

52.6

26.7

0.6465

0.1970

4

0.2043

5.189

4.89

1.93

41.7

21.2

0.8152

0.2485

5

0.1819

4.621

5.50

2.16

33.1

16.8

1.028

0.3133

6

0.1620

4.115

6.17

2.43

26.3

13.3

1.296

0.3951

7

0.1443

3.665

6.93

2.73

20.8

10.5

1.634

0.4982

8

0.1285

3.264

7.78

3.06

16.5

8.37

2.061

0.6282

9

0.1144

2.906

8.74

3.44

13.1

6.63

2.599

0.7921

10

0.1019

2.588

9.81

3.86

10.4

5.26

3.277

0.9989

11

0.0907

2.305

11.0

4.34

8.23

4.17

4.132

1.260

12

0.0808

2.053

12.4

4.87

6.53

3.31

5.211

1.588

13

0.0720

1.828

13.9

5.47

5.18

2.62

6.571

2.003

14

0.0641

1.628

15.6

6.14

4.11

2.08

8.286

2.525

15

0.0571

1.450

17.5

6.90

3.26

1.65

10.45

3.184

16

0.0508

1.291

19.7

7.75

2.58

1.31

13.17

4.016

17

0.0453

1.150

22.1

8.70

2.05

1.04

16.61

5.064

18

0.0403

1.024

24.8

9.77

1.62

0.823

20.95

6.385

19

0.0359

0.912

27.9

11.0

1.29

0.653

26.42

8.051

20

0.0320

0.812

31.3

12.3

1.02

0.518

33.31

10.15

21

0.0285

0.723

35.1

13.8

0.810

0.410

42.00

12.80

22

0.0253

0.644

39.5

15.5

0.642

0.326

52.96

16.14

23

0.0226

0.573

44.3

17.4

0.509

0.258

66.79

20.36

24

0.0201

0.511

49.7

19.6

0.404

0.205

84.22

25.67

25

0.0179

0.455

55.9

22.0

0.320

0.162

106.2

32.37

26

0.0159

0.405

62.7

24.7

0.254

0.129

133.9

40.81

27

0.0142

0.361

70.4

27.7

0.202

0.102

168.9

51.47

28

0.0126

0.321

79.1

31.1

0.160

0.0810

212.9

64.90

29

0.0113

0.286

88.8

35.0

0.127

0.0642

268.5

81.84

30

0.0100

0.255

99.7

39.3

0.101

0.0509

338.6

103.2

31

0.00893

0.227

112

44.1

0.0797

0.0404

426.9

130.1

32

0.00795

0.202

126

49.5

0.0632

0.0320

538.3

164.1

33

0.00708

0.180

141

55.6

0.0501

0.0254

678.8

206.9

34

0.00630

0.160

159

62.4

0.0398

0.0201

856.0

260.9

35

0.00561

0.143

178

70.1

0.0315

0.0160

1079

329.0

36

0.00500

0.127

200

78.7

0.0250

0.0127

1361

414.8

37

0.00445

0.113

225

88.4

0.0198

0.0100

1716

523.1

38

0.00397

0.101

252

99.3

0.0157

0.00797

2164

659.6

39

0.00353

0.0897

283

111

0.0125

0.00632

2729

831.8

40

0.00314

0.0799

318

125

0.00989

0.00501

3441

1049

*This AWG chart is for a single, solid, round conductor. The AWG of a stranded wire is determined by the total cross-sectional area of the conductor, which determines its current-carrying capacity and electrical resistance. There are also small gaps between the strands, therefore a stranded wire will always have a slightly larger overall diameter than a solid wire with the same AWG.

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