There is no single armoured cable size that is correct for every UK home EV charger. A 7 kW charger draws about 32 amps. The installer chooses the conductor size for that current, the installation method, the length and the voltage drop. Six millimetre and ten millimetre steel-wire armoured cables are both common in domestic quotes. Which one is right is a calculation, not a slogan.
Write what size armoured cable for a home EV charger into the quote
The quote should state cable type, conductor size, approximate length, whether it is buried or surface, and who makes good the finishes. If size is written as 'TBC' after you have paid, you do not have a price.
What size armoured cable for a home EV charger
Long runs to a garage or a post at the end of a drive are where a larger conductor, or a different route, earns its place. A short run on a surface from a nearby consumer unit is a different job. Clipped direct, buried, or run through insulation all change the rating.
- 32 amp circuits for 7 kW need a calculated conductor size
- Length and burial change the answer
- No universal 6 mm or 10 mm rule
- Joints and route are part of the spec
Check what size armoured cable for a home EV charger before you accept a price
Measure the route the cable will really take, including vertical rises, not the straight line on a satellite photo. Tell the installer if the cable must be buried under a drive that is about to be block-paved.
The price effect of what size armoured cable for a home EV charger
Undersizing to save a few metres of copper is a false economy if the circuit fails voltage drop or cannot be certified. Oversizing everything to ten millimetre without a reason is just cost. The written calculation, or at least the stated size and length, is what you compare.
A miss that shows up later: what size armoured cable for a home EV charger
Copying a cable size from a neighbour ignores your length and your route. Adding joints to use up offcuts in a wet garden is another avoidable failure point.
Frequently asked questions
Is 6 mm SWA always enough?
Not always. It is often used on shorter 32 amp runs and it is wrong on some longer or hotter routes. The installer calculates it.
Is 10 mm the safe default?
It is sometimes the right answer and sometimes wasted money. Ask why it was chosen for your length.
Can I bury ordinary grey twin and earth?
No. The cable type has to suit the route. Buried runs use an appropriate armoured or equivalent protected design.
Who signs for the size?
The installer who certifies the circuit. Keep that certificate with the house papers.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
How this guide was prepared
This guide was written by the Local EV Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.