Wire sizes: AWG and mm²
Compare gauges and convert sizes. Get 10 right to finish. US asks about AWG; IEC asks for the metric size.
About how big is the copper cross-section of 14 AWG wire?
AWG counts backwards
US drawings give wire sizes in AWG (American Wire Gauge). The number comes from how many times the wire was drawn through a die, so a higher number means a thinner wire. European drawings give the copper cross-section in mm².
| AWG | Area (mm²) | Diameter (mm) | Next metric size up |
|---|---|---|---|
| 16 | 1.31 | 1.29 | 1.5 mm² |
| 14 | 2.08 | 1.63 | 2.5 mm² |
| 12 | 3.31 | 2.05 | 4 mm² |
| 10 | 5.26 | 2.59 | 6 mm² |
| 8 | 8.37 | 3.26 | 10 mm² |
| 6 | 13.3 | 4.12 | 16 mm² |
| 4 | 21.2 | 5.19 | 25 mm² |
When you swap an AWG size for a metric one, go to the next size up, never down. The wire must carry at least as much current as the drawing asks for.
Questions
- Is a higher AWG number thicker or thinner?
- Thinner. 14 AWG is thinner than 12 AWG. Going down 3 gauge numbers roughly doubles the copper area.
- What is 12 AWG in mm²?
- About 3.31 mm². The next standard metric size up is 4 mm².
Explained in our own words and checked against several references. For the full rules, see the NEC (NFPA 70), NFPA 79, IEC 60617, IEC 60445 and IEC 81346-2. Your drawing legend always comes first.