AWG to mm² and mm² to AWG
Convert wire size from American Wire Gauge to square millimetres and back — accurate conversion table.
What is AWG
AWG (American Wire Gauge) is the US wire sizing system. The smaller the number, the thicker the wire: 4/0 — 107 mm², 14 AWG — 2.08 mm², 22 AWG — 0.326 mm². Formula: d = 0.127×92^((36−n)/39) mm.
Conversion table
| AWG | mm² | Ampacity 75°C (copper, NEC 310.16) |
|---|---|---|
| 4/0 | 107.2 | 230 A |
| 1/0 | 53.5 | 150 A |
| 2 | 33.6 | 115 A |
| 6 | 13.3 | 65 A |
| 8 | 8.37 | 50 A |
| 10 | 5.26 | 35 A |
| 12 | 3.31 | 25 A |
| 14 | 2.08 | 20 A |
| 16 | 1.31 | 18 A |
| 18 | 0.823 | 14 A |
How to use
Choose the direction: AWG → mm² (for IEC/REBT sizing) or mm² → AWG (for NEC sizing). To size a conductor by current use the cable calculator.
Related calculators
- Cable size by current — cable-calculator
- Breaker selection — breaker-selector
- Watts to amps — watts-amps
FAQ
What AWG is 2.5 mm²?
The closest is 13 AWG (2.62 mm²) or 14 AWG (2.08 mm²). By ampacity 2.5 mm² ≈ 14 AWG (20 A at 75°C).
What is AWG 12 in mm²?
3.31 mm². Per NEC 310.16 at 75°C — 25 A, similar to IEC 4 mm² by ampacity.
Is thicker always better?
No: size by current, voltage drop and installation method. Thicker is more expensive and harder to install.