Cable Size Guide

The Gauge Guide bullets will help you determine the overall size (including insulation) of an unmarked cable. 

Actual diameters may vary depending on the age, make and insulation thickness of your cable. 

If you are still not sure, the most accurate way to measure your cable is to determine the area in mm² of the copper conductors.

As an example, let's assume we want to know the area for 6 B&S cable:


  • Count the total number of strands. (168)
  • Measure the diameter of one of the strands. (0.32)

 

In this case we have 168 strands @ 0.32mm each. Knowing this we now do the following calculations:


  • Square (multiply by itself) the diameter of each strand (0.32 × 0.32 = 0.1024)
  • Multiply this result  x (Pi) 3.142  (0.1024 x 3.142 = 0.3217408)
  • Divide this result by 4 (0.321536/4 = 0.0804352)
  • Multiply this result by the number of strands (0.0804352 x 168 = 13.5131136)

 

Therefore the approximate area for 6 B&S cable is 13.50mm²

 

 

Cable Size & Diameters

Cable Size

Nom Area mm²

Nom O.D.mm

Amp Rating

Part # Prefix

Gauge Guide

8 B&S

7.71

5.5

74

C8

6 B&S

13.5

7.2

103

C6

4 B&S

20.26

8.3

135

C4

3 B&S

26.45

10.2

168

C3

2 B&S

32.07

11.3

188

C2

1 B&S

39.55

12.1

210

C1

0 B&S

49.00

12.7

246

C0

00 B&S

64.15

14.5

292

C00

000 B&S

83.19

16.4

335

C000

0000 B&S

99.27

17.5

399

C0000

Twin 8 B&S

7.71

7.1 x 12.5

59

C2TS-8

Twin 6 B&S

13.5

8.8 x 16

82

C2TS-6

Twin 4 B&S

20.26

10.3 x 18.6

108

C2TS-4

Twin 2 B&S

32.07

13.4 x 24.6

150

C2TS-2

 

 

Vehicle Applications

8 B&S (7.71mm²):
  • Dual battery systems
  • Accessory leads
  • Caravans
  • Low power alternators
  • Auxiliary power application up to 74amp

 

 

6 B&S (13.50mm²):
  • Dual battery systems
  • Accessory leads
  • Caravans
  • Some standard alternators
  • Battery cables for small engines
  • Auxiliary power application up to 103amp

 

 

4 B&S (20.26mm²):
  • Dual battery systems
  • Accessory leads
  • Caravans
  • Alternators up to 160A
  • Battery cables for standard engines
  • Auxiliary power application up to 135amp

 

 

3 B&S (26.45mm²):
  • Dual battery systems
  • Accessory leads
  • Caravans
  • Alternators up to 160A
  • Battery cables for standard engines
  • Auxiliary power application up to 168amp

 

 

2 B&S (32.07mm²):
  • Dual battery systems
  • High powered accessory leads (winches, inverters)
  • Caravans
  • Alternators 160A - 180A
  • Battery cables for 4 & 6 cylinder engines
  • Jumper Cables for standard engines
  • Auxiliary power application up to 188amp

 

 

1 B&S (39.55mm²):
  • Dual battery systems
  • High powered accessory leads (winches, inverters)
  • Caravans
  • Alternators up to 200A
  • Battery cables for larger 6 cylinder & small V8  engines
  • Auxiliary power applications up to 210amp

 

 

0 B&S (49.00mm²):
  • Dual battery systems
  • High powered accessory leads (winches, inverters)
  • Caravans
  • Smaller trucks & diesel engines
  • Battery cables for high performance 6 cylinder & standard V8 engines
  • Jumper Cables for larger engines
  • Auxiliary power applications up to 246amp

 

 

00 B&S (64.15mm²):
  • Dual battery systems
  • High powered accessory leads (winches, inverters)
  • Caravans
  • Trucks & diesel engines
  • Battery cables for high compression & large V8 engines
  • Jumper Cables for very large engines
  • Auxiliary power applications up to 292amp

 

 

000 B&S (83.19mm²):
  • Dual battery systems
  • High powered accessory leads (winches, inverters)
  • Caravans
  • Large trucks, diesel & marine engines
  • Battery cables for very large high performance engines
  • Auxiliary power applications up to 335amp

 

 

0000 B&S (99.27mm²):
  • Dual battery systems
  • High powered accessory leads (winches, inverters)
  • Caravans
  • Large trucks, diesel & marine engines
  • Battery cables for very large high performance engines
  • Auxiliary power applications up to 399amp

 

 

Extended Lengths

It is recommended for applications over 5m in length that you increase the cable gauge by at least one size.

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