One and a half kilometres; the distance to anywhere from anywhere else; a long way. Example: Where's Christie's Beach? About a kay and a half that way. How far are we from home? We'd be a good kay and a half, I reckon.
A (GOOD) KAY AND A HALF
Meaning of A (GOOD) KAY AND A HALF in English
Slang English vocab. Английский сленговый словарь. 2012