what size of viv would i need for a king snake

[csh]

hi just a quick question what size of viv would i need in end for a king snake ??? its in a36 by 16 @ moment but ive a corn snake that needs upgrading as well ,well would the king snakes old tank be big enough for life for corn snake ? sorry this is 2 questions

[spend_day]

depends on the species of king snake and it size a florida king can hit 6foot where a smaller species like a pairie kingsnake only normally get to 3-4 foot

I dont keep snakes but i think the general rule is lenght+width of the viv must at least = the lenght of the snake