# Wire Sizes

Wires sizes are expressed is a few different ways. In the USA, AWG (American Wire Gauge) is most common. In Australia, CSA (Cross Sectional Area) is the most often used term.

The CSA is calculated as: Number of strands * Pi * (Strand radius squared)

For example, a 24/0.2 cable is: 24 * Pi * (0.1 * 0.1) which gives approx 0.754 sq mm CSA.

## Comparison Chart

The "Metric Strands" column lists common wire sizes found in Australia.

Use the "Resistance" column figures in conjunction with the [[Ohms Law]] page to help determine how much voltage drop you'll get in your situation.

Please note that the "Rating (Amps)" figures are a guide only, and may need de-rating when cables are bundled together, enclosed in conduit or subject to high ambient temperatures.

AWGCSA (sq mm)Metric StandsResistanceRating (Amps)
(Ω/km)(Ω/kFT)
142.4
233.6
326.70.64650.1970
25.7364/0.3200
421.20.81520.2485
516.8
613.31.2960.3951
710.5
88.372.0610.6282
96.63
7.1630/0.1261
105.263.2770.9989
114.17
123.315.2111.588
132.4550/0.256.5712.00322
2.390/0.1820
142.088.2862.525
151.65
161.3113.174.016
171.0432/0.216.615.06410
180.82320.956.385
0.75424/0.27.5
190.65326.428.051
200.51816/0.2 or 20/0.1833.3110.155
0.4414/0.24.5
210.41
220.32652.9616.14
230.258
0.227/0.22.2
0.21514/0.142
240.20584.2225.67
250.162
0.147/0.161.5
260.1297/0.15133.940.81
270.102
280.087/0.12212.964.9

## References

Categories:

• Created by
on
Last updated by
on
• Contributors:

• Normal page