AWG (American Wire Gauge) is the standard system for specifying the diameter of round, solid conductors, in use since 1857. The AWG number and the wire diameter move in opposite directions: a larger AWG number means a thinner wire, because each step up the gauge scale corresponds to another pass through a progressively smaller drawing die. AWG 4/0 (the thickest standard gauge) is roughly 11.7mm in diameter, while AWG 40 (the thinnest) is under 0.1mm. For engineers and buyers working in metric units, this chart also gives you the direct mm² equivalent, which is what matters when matching wire to a Cut & Strip machine's rated processing range.
AWG to Diameter, Area, Resistance & Weight
| AWG |
Diameter (mm) |
Area (mm²) |
Resistance (Ω/km) |
Weight (kg/km) |
| 4/0 |
11.68 |
107.2 |
0.161 |
953.2 |
| 3/0 |
10.40 |
85.03 |
0.203 |
755.9 |
| 2/0 |
9.266 |
67.43 |
0.256 |
599.5 |
| 1/0 |
8.251 |
53.48 |
0.322 |
475.4 |
| 1 |
7.348 |
42.41 |
0.407 |
377.0 |
| 2 |
6.544 |
33.63 |
0.513 |
299.0 |
| 3 |
5.827 |
26.67 |
0.646 |
237.1 |
| 4 |
5.189 |
21.15 |
0.815 |
188.0 |
| 5 |
4.621 |
16.77 |
1.028 |
149.1 |
| 6 |
4.115 |
13.30 |
1.296 |
118.2 |
| 7 |
3.665 |
10.55 |
1.634 |
93.78 |
| 8 |
3.264 |
8.366 |
2.061 |
74.37 |
| 9 |
2.906 |
6.634 |
2.599 |
58.98 |
| 10 |
2.588 |
5.261 |
3.277 |
46.77 |
| 11 |
2.305 |
4.172 |
4.132 |
37.09 |
| 12 |
2.053 |
3.309 |
5.211 |
29.42 |
| 13 |
1.828 |
2.624 |
6.571 |
23.33 |
| 14 |
1.628 |
2.081 |
8.285 |
18.50 |
| 15 |
1.450 |
1.650 |
10.45 |
14.67 |
| 16 |
1.291 |
1.309 |
13.17 |
11.63 |
| 17 |
1.150 |
1.038 |
16.61 |
9.226 |
| 18 |
1.024 |
0.823 |
20.95 |
7.317 |
| 19 |
0.912 |
0.653 |
26.41 |
5.803 |
| 20 |
0.812 |
0.518 |
33.31 |
4.602 |
| 21 |
0.723 |
0.410 |
42.00 |
3.649 |
| 22 |
0.644 |
0.326 |
52.96 |
2.894 |
| 23 |
0.573 |
0.258 |
66.78 |
2.295 |
| 24 |
0.511 |
0.205 |
84.21 |
1.820 |
| 25 |
0.455 |
0.162 |
106.2 |
1.443 |
| 26 |
0.405 |
0.129 |
133.9 |
1.145 |
| 27 |
0.361 |
0.102 |
168.9 |
0.908 |
| 28 |
0.321 |
0.081 |
212.9 |
0.720 |
| 29 |
0.286 |
0.064 |
268.5 |
0.571 |
| 30 |
0.255 |
0.051 |
338.6 |
0.453 |
| 32 |
0.202 |
0.032 |
538.3 |
0.285 |
| 34 |
0.160 |
0.020 |
856.0 |
0.179 |
| 36 |
0.127 |
0.013 |
1361 |
0.113 |
| 38 |
0.101 |
0.008 |
2164 |
0.071 |
| 40 |
0.080 |
0.005 |
3441 |
0.045 |
Values calculated from the standard AWG geometric formula (d = 0.005 × 92((36−n)/39) inch) using annealed copper resistivity of 0.017241 Ω·mm²/m at 20°C and copper density of 8.89 g/cm³. Actual resistance and weight may vary slightly by manufacturer based on copper purity and drawing process.
Wire Resistance: R = ρL/A
Resistivity (ρ, the Greek letter rho) is a property of the conductor material itself: the resistance of a sample of that material exactly 1 meter long with a cross-sectional area of 1mm², measured at room temperature (20°C). Wire resistance is then calculated from resistivity using R = ρL/A, where R is total resistance in ohms, L is conductor length in meters, and A is cross-sectional area in mm². Annealed copper has a resistivity of approximately 0.017241 Ω·mm²/m, which is the constant used to calculate the resistance column above.
AWG vs. Cut & Strip Machine Range
EASTONTECH's Cut & Strip lines are organized by mm² wire range rather than AWG, since most production specs outside North America are written in metric. Use the area column above to cross-reference: our 0-35mm² Cut & Strip machines cover roughly AWG 4 through AWG 40, which spans the great majority of signal and light-gauge automotive wiring, while our 50-400mm² Cut & Strip machines are built for heavier power cable, corresponding to wire thicker than AWG 4/0.
Frequently Asked Questions(FAQ)
Q: Does a bigger AWG number mean a thicker or thinner wire?
A: A bigger AWG number means a thinner wire. The AWG scale runs in reverse of physical size, so AWG 40 is one of the thinnest standard gauges while AWG 4/0 is one of the thickest.
Q: How do I convert AWG to mm²?
A: Use the area column in the table above for the exact standard value at each gauge. As a rough rule of thumb, every 3 AWG steps roughly doubles or halves the cross-sectional area.
Q: Why does resistance increase so much between 10 AWG and 40 AWG?
A: Resistance is inversely proportional to cross-sectional area, and area shrinks with the square of the diameter. Going from 10 AWG to 40 AWG reduces the diameter by roughly 32 times, so the cross-sectional area, and therefore the resistance per unit length, changes by a much larger factor.
Q: Are AWG values the same for stranded and solid wire?
A: The AWG number refers to the equivalent total cross-sectional area of copper, so a stranded conductor at a given AWG carries the same rated area as its solid equivalent, but its overall outer diameter is slightly larger due to the air gaps between individual strands.
