AWG to mm Converter
| AWG | Diameter (mm) | Area (mm²) | Typical role |
|---|---|---|---|
| 4/0 (0000) | 11.68 | 107.22 | service entrance, 200 A |
| 2 | 6.54 | 33.63 | 100 A sub-panel feed |
| 6 | 4.12 | 13.30 | central AC / water heater |
| 8 | 3.26 | 8.37 | electric dryer / range branch |
| 10 | 2.59 | 5.26 | water heater / window AC (30 A) |
| 12 | 2.05 | 3.31 | kitchen and bathroom outlets (20 A) |
| 14 | 1.63 | 2.08 | lighting circuits (15 A) |
| 16 | 1.29 | 1.31 | light-duty extension cords |
| 18 | 1.02 | 0.82 | lamp and fixture cords |
| 20 | 0.81 | 0.52 | automotive, low-voltage DC |
| 22 | 0.64 | 0.33 | breadboard jumper wire |
| 24 | 0.51 | 0.20 | telecom and thermostat wire |
One formula runs the entire American Wire Gauge: diameter in mm = 0.127 × 92^((36-n)/39). The gauge everyone asks about first: 12 AWG, the kitchen- and bathroom-outlet wire, is 2.05 mm across carrying 3.31 mm² of copper; household lighting 14 AWG is 1.63 mm and 2.08 mm²; the 4/0 service-entrance giant is 11.68 mm and 107 mm². Type a gauge - aughts welcome (4/0, 00, 2) - and the converter gives millimetre diameter and cross-section live, or type a diameter to land on the nearest gauge.
This page earns its keep at the border between two wire vocabularies: Europe sells copper by cross-section (1.5 mm², 2.5 mm², 4 mm²) and America by gauge number, and neither label translates itself. The table lines up the gauges you actually meet, from the 200-amp service feed down to thermostat wire, so a European 2.5 mm² spool stops being a guessing game against an American 14-AWG spec sheet.
How to use
- Type the gauge as printed: plain numbers (12) or aughts (00, 3/0) - diameter and area appear instantly.
- Or paste a metric diameter in mm to get the nearest AWG size back.
- Match the table row to your job - the roles column reflects common North American branch-circuit practice, not a substitute for your local code.
Frequently asked questions
What AWG is 2.5 mm² wire?
2.5 mm² is the everyday European outlet wire and sits nearest to 14 AWG (2.08 mm²), with 13 AWG (2.62 mm²) as the slightly-over twin. Practical translation: 1.5 mm² ≈ 16 AWG, 2.5 mm² ≈ 14 AWG, 4 mm² ≈ 12 AWG, 6 mm² ≈ 10 AWG, 10 mm² ≈ 8 AWG. Note the direction of the rounding: the metric size carries slightly more copper than its gauge nickname, so the gauge name is the conservative answer.
Why does bigger wire have a smaller gauge number?
AWG started as a count of manufacturing steps: wire was pulled through a draw plate, and each pass through a smaller hole added one gauge number. Starting from 36 AWG (0.127 mm, the smallest size on the original plate) every three gauge steps halve the diameter and every six steps quarter the cross-sectional area - which is why 12 AWG (3.31 mm²) has four times the copper of 18 AWG (0.82 mm²). The number counts how far the wire travelled down the plate, not how thick it is.
What do 4/0 and 00 mean? What is aught?
Aught is the old word for zero, and heavy cables switch to it: 1/0 (spoken one-aught) is the size just past 1 AWG, 2/0 just past that, and so on. The anchors: 0 AWG is 8.25 mm across, 00 (2/0) is 9.27 mm, 000 (3/0) is 10.40 mm, and 4/0 (0000) is 11.68 mm with 107 mm² of copper - the largest size the gauge system defines. Inside the formula the aughts count backwards as n = 0, -1, -2, -3 while ordinary gauges count down from 36. Type 4/0 or 0000 in the converter; both parse.
Is stranded wire the same gauge as solid?
Yes for copper content, no for calipers. A 12-AWG stranded conductor bundles finer strands to the same 3.31 mm² of copper, so it carries the same ampacity but measures slightly over 2.05 mm across (stranding adds air gaps and a compressing wrapper). Terminations differ too: stranded wire into a screw terminal wants a ferrule to stop stray strands, and fine-stranded classes flex better in cords while solid holds shape better in branches.
How many amps can each gauge carry?
North American branch-circuit anchors: 14 AWG protects at 15 A, 12 AWG at 20 A, 10 AWG at 30 A - the lighting/outlet/water-heater trio in the table. Larger feeders scale with copper: 6 AWG serves central-AC and water-heater circuits, 2 AWG feeds 100-amp sub-panels, 4/0 serves 200-amp services. Continuous loads should sit at 80% of the breaker, and local codes plus cable type and temperature rating always win over any generic table.