AWG to mm² Wire Gauge Converter
Type a gauge or a cross-section. Everything is computed live in your browser from the standard AWG formula — no lookup rounding, no network calls.
Accepts 4/0, 0000, 00, 0 and 1–40
- Area
- 3.309 mm²
- Diameter
- 2.053 mm
- Diameter
- 0.081 in
Finds the nearest standard AWG size
- Nearest AWG
- 12
- Diameter
- 2.053 mm
- AWG area
- 3.309 mm²
AWG reference chart
Click any column header to sort. The highlighted row follows the converter above. Current values are approximate free-air, single-conductor figures — for reference only, consult your local electrical code for actual ampacity ratings.
| 0000 (4/0) | 11.684 | 0.4600 | 107.219 | 380 |
| 000 (3/0) | 10.405 | 0.4096 | 85.029 | 328 |
| 00 (2/0) | 9.266 | 0.3648 | 67.431 | 283 |
| 0 (1/0) | 8.251 | 0.3249 | 53.475 | 245 |
| 1 | 7.348 | 0.2893 | 42.408 | 211 |
| 2 | 6.544 | 0.2576 | 33.631 | 181 |
| 3 | 5.827 | 0.2294 | 26.670 | 158 |
| 4 | 5.189 | 0.2043 | 21.151 | 135 |
| 5 | 4.621 | 0.1819 | 16.773 | 118 |
| 6 | 4.115 | 0.1620 | 13.302 | 101 |
| 7 | 3.665 | 0.1443 | 10.549 | 89 |
| 8 | 3.264 | 0.1285 | 8.366 | 73 |
| 9 | 2.906 | 0.1144 | 6.634 | 64 |
| 10 | 2.588 | 0.1019 | 5.261 | 55 |
| 11 | 2.305 | 0.0907 | 4.172 | 47 |
| 12 | 2.053 | 0.0808 | 3.309 | 41 |
| 13 | 1.828 | 0.0720 | 2.624 | 35 |
| 14 | 1.628 | 0.0641 | 2.081 | 32 |
| 15 | 1.450 | 0.0571 | 1.650 | 28 |
| 16 | 1.291 | 0.0508 | 1.309 | 22 |
| 17 | 1.150 | 0.0453 | 1.038 | 19 |
| 18 | 1.024 | 0.0403 | 0.823 | 16 |
| 19 | 0.912 | 0.0359 | 0.653 | 14 |
| 20 | 0.812 | 0.0320 | 0.518 | 11 |
| 21 | 0.723 | 0.0285 | 0.410 | 9 |
| 22 | 0.644 | 0.0253 | 0.326 | 7 |
| 23 | 0.573 | 0.0226 | 0.258 | 4.7 |
| 24 | 0.511 | 0.0201 | 0.205 | 3.5 |
| 25 | 0.455 | 0.0179 | 0.162 | 2.7 |
| 26 | 0.405 | 0.0159 | 0.129 | 2.2 |
| 27 | 0.361 | 0.0142 | 0.102 | 1.7 |
| 28 | 0.321 | 0.0126 | 0.081 | 1.4 |
| 29 | 0.286 | 0.0113 | 0.064 | 1.2 |
| 30 | 0.255 | 0.0100 | 0.051 | 0.86 |
| 31 | 0.227 | 0.0089 | 0.040 | 0.70 |
| 32 | 0.202 | 0.0080 | 0.032 | 0.53 |
| 33 | 0.180 | 0.0071 | 0.025 | 0.43 |
| 34 | 0.160 | 0.0063 | 0.020 | 0.33 |
| 35 | 0.143 | 0.0056 | 0.016 | 0.27 |
| 36 | 0.127 | 0.0050 | 0.013 | 0.21 |
| 37 | 0.113 | 0.0045 | 0.010 | 0.17 |
| 38 | 0.101 | 0.0040 | 0.008 | 0.13 |
| 39 | 0.090 | 0.0035 | 0.006 | 0.11 |
| 40 | 0.080 | 0.0031 | 0.005 | 0.09 |
How the AWG scale actually works
AWG is not a measurement, it is a count. Wire is made by pulling a rod through a series of progressively smaller dies, and the gauge number records how many drawing passes it took. That is why the numbers run backwards: 30 AWG has been through more dies than 10 AWG, so it is thinner. The scale was later pinned to two fixed endpoints — 0000 at 0.46 in and 36 AWG at 0.005 in — with 39 equal ratio steps between them, which gives the formula d = 0.127 × 92^((36 − n) / 39) in millimetres.
Because each step is a constant ratio rather than a constant amount, the scale is logarithmic. Every 6 gauges the diameter roughly doubles, every 3 gauges the cross-sectional area roughly doubles, and every 10 gauges the area changes by about a factor of 10. Those shortcuts are exact enough for field work and are the reason experienced electricians can size wire without a chart. It also explains why the sizes above 0 need their own notation: 00, 000 and 0000 are simply gauges −1, −2 and −3 in the same sequence.
Practically, this matters whenever US and metric specifications meet. IEC and European cable is specified directly by conductor area in mm² — 1.5, 2.5, 4, 6, 10 — and those values never land exactly on an AWG size. Converting gives you the nearest gauge, not an equivalent part: 2.5 mm² sits between 14 and 13 AWG, so a designer substituting for a 12 AWG US circuit needs to check ampacity, termination size and derating rather than assuming the nearest number is a drop-in. Always size on area and the applicable code table, and use the gauge number only as a label.
Frequently asked questions
What is 2.5mm² wire in AWG?
- 2.5 mm² is closest to AWG 13 (2.624 mm²), and in practice is treated as the metric equivalent of AWG 14 (2.081 mm²) in most wiring applications. Since AWG 13 is rarely stocked, a 2.5 mm² cable is usually substituted for 14 AWG — and it is slightly thicker, so it is the conservative choice.
Is a bigger or smaller AWG number a thicker wire?
- A smaller AWG number means a thicker wire. The gauge counts drawing operations, so 10 AWG is much thicker than 20 AWG, and the 0, 00, 000 and 0000 sizes are thicker still.
How do I convert AWG to square mm by hand?
- Compute the diameter first: d(mm) = 0.127 × 92^((36 − n) / 39), where n is the gauge number (use −1, −2 and −3 for 00, 000 and 0000). Then area = π × (d/2)². For a quick mental check, area roughly doubles every three gauges down.
What AWG is equivalent to standard European cable sizes?
- 1.0 mm² ≈ 17 AWG (commonly swapped for 16 AWG), 1.5 mm² ≈ 15 AWG (commonly 14 AWG), 2.5 mm² ≈ 13 AWG (commonly 12 AWG for equivalent ampacity), 4 mm² ≈ 11 AWG, 6 mm² ≈ 9 AWG, 10 mm² ≈ 7 AWG and 16 mm² ≈ 5 AWG. Metric sizes are nominal conductor areas, so they almost never land exactly on an AWG size.
Why does area double every three AWG sizes?
- Each gauge step multiplies the diameter by 92^(1/39) ≈ 1.1229. Three steps multiply diameter by about 1.26, and since area scales with the square of diameter, that is a factor of roughly 2.
Can I use this converter for stranded wire?
- Yes for the conductor cross-section, which is what ampacity depends on, but not for the physical outside diameter. A stranded conductor of a given AWG has the same nominal copper area but a larger overall diameter than solid wire because of the gaps between strands.