Correct cable size for kill switch

[MikeInEssex]

As per the title, what is the correct size wire to use for a battery kill switch?

[Chris32345]

Same size as whatever the main cable is currently

[jetbox]

Is this for a motorsport application or just to disable the battery?

[Penelope Stopit]

Depends on what starter current is being drawn through it and how far away it is from the starter