Automotive Cable Amp Rating Chart
This automotive cable amp rating chart shows typical current capacity for common thin wall and standard PVC automotive cable sizes used in 12V vehicle wiring, campervan electrics, garages and split charge systems in the UK.
Automotive cable amp rating chart (quick reference)
| Cable Size (CSA) | Thin Wall (TWA) | Standard PVC (SE / BS6862) | Typical Uses |
|---|---|---|---|
| 0.50mm² | 11A | — | Sensors, signal wiring |
| 0.65mm² | — | 5.75A | Low current control wiring |
| 0.75mm² | 14A | — | Control circuits, light-duty wiring |
| 1.00mm² | 16.5A | 8.75A | Lighting circuits |
| 1.50mm² | 21A | 12.75A | Interior accessories, LED circuits |
| 2.00mm² | 25A | 17.95A | Pumps, auxiliary feeds |
| 2.50mm² | 29A | 21.75A | 12V sockets, medium accessory circuits |
| 3.00mm² | 33A | 27.5A | Fridge circuits, heavier auxiliaries |
| 4.00mm² | 39A | 32A | Split charge relay feeds |
| 4.50mm² | 42A | 35A | Auxiliary battery wiring |
| 6.00mm² | 50A | 42A | DC-DC charger supply cables |
| 7.00mm² | — | 50A | Higher load standard cable circuits |
| 8.50mm² | 63A | 60A | High load charging circuits |
| 10.00mm² | 70A | 70A | Battery charging cables |
| 16.00mm² | 110A | — | Alternator to leisure battery feeds |
| 25.00mm² | 170A | — | Inverter supply cables |
Visual cable size vs current capacity comparison
Why thin wall automotive cable often carries more current
Thin wall cable is designed for modern vehicle wiring systems and often uses insulation with higher temperature performance than older standard PVC cable. That allows better harness performance in many automotive installations.
- Higher temperature insulation rating
- Modern vehicle harness specification
- More efficient use of loom space
- Widely used in OEM and retrofit automotive wiring
How cable length affects amp rating in real installations
Even if a cable has a published current rating, longer cable runs can still create voltage drop problems in 12V systems. That means amp rating alone is not always enough when selecting automotive cable.
- Short cable runs usually perform better
- Longer runs increase voltage loss
- Low voltage systems are especially sensitive to cable length
- Battery charging and fridge circuits often need upsizing
Typical automotive cable size selection examples
| Application | Typical Cable Choice |
|---|---|
| LED lighting circuits | 1.0mm² to 1.5mm² |
| Water pump circuits | 2.0mm² |
| 12V auxiliary sockets | 2.5mm² |
| Fridge circuits | 2.5mm² to 4.0mm² |
| Split charge relay wiring | 4.0mm² to 6.0mm² |
| DC-DC charger installation | 6.0mm² to 16.0mm² |
| Inverter supply cables | 16.0mm² to 35.0mm²+ |
Helpful tools for automotive cable selection
Related automotive cable guides
Select the correct cable size before installation
Correct cable sizing improves safety, reduces voltage drop and protects electrical components in automotive and 12V systems.
Open Cable Size CalculatorElectrical installation safety notice
This automotive cable amp rating chart is provided as a general reference for typical 12V vehicle wiring installations.
Cable capacity depends on installation conditions including cable length, routing method, ambient temperature, insulation type and bundling inside wiring looms.
Always confirm manufacturer specifications before selecting cable for high-current automotive electrical systems.