Cables are usually sized directly using the metric diameter or the American wire gauge (AWG). An increasing wire size decreases the gauge of the wire. The AWG scale spans from 11.684mm to 0.0779mm (No. 0000 AWG to No. 40 AWG) with 39 step sizes in between. Cable size is an important parameter which directly correlates to the cross sectional area of the wire, which affects the electrical (conductance and resistance) and mechanical properties of the wire.

- Skill level:
- Moderately Easy

### Other People Are Reading

## Instructions

- 1
Convert the metric wire diameter into millimetres. For example, if the wire diameter is given as 0.005827 meters, multiple by a factor of 1,000 to obtain 5.827 millimetres.

- 2
Input the wire diameter (in millimetres) into the equation AWG = (-ln(d)+2.1104)/(0.11594), where d is the wire diameter in millimetres and AWG is the American wire gauge number. A wire diameter of 6.544 millimetres equates to a No. 2 AWG wire.

- 3
Reconvert wire given in AWG to a metric wire size using the equation d = exp^(2.1104-0.11594*AWG). Using this equation, a No. 1 AWG wire has a diameter of 6.544 millimetres.

#### Tips and warnings

- An increasing wire diameter decreases the AWG number. Doubling the wire diameter decreases the AWG by 6 units.
- The above conversions do not apply to steel wiring. An alternative scale is used to size wires of this material.