A pot sized reraise would be to $68. With KK, you have several different options for playing in this spot which all have valid arguments, some are more profitable than others depending on how the other players play pre flop and post flop. If you can get this hand heads up or maybe 3 ways with a pot sized raise, then that should be your standard line. But you'll want to mix up your range with a few non premium hands as well to mix up your play (for instance, you may want to do the same in this spot with all your JTs hands and hands like 77 or 88 but not 99, TT, or possibly even JJ). However, if a pot sized raise will just scare everyone off, then you're leaving money on the table, which is never a good thing. The key here is to figure out the right balance between maximizing profit, managing the pot size, and avoiding difficult spots post flop (this means reraising enough so that your opponents are dissuaded from calling with weaker hands like 22-55, 64s, etc.). If you raise too light, everyone will want to join in because their implied odds are so big that they can show a long term profit with good post flop play with weaker hands.
The absolute minimum I would reraise to would be about $45 in this spot, and even that is practically begging for a 3 way pot in most games. A pot sized raise to $68 or a raise to $60 is more likely to get it heads up pre flop with you in position - which is what you really want. Once you've built a nice heads up pot, players will try to fight for the money in the middle and are much more likely to pay you off with weaker holdings post flop, or even try to steal against you. Whereas if there are 4 or more players in there, they are more likely to trap or play draw hands fast, putting you in a difficult position - often with the best hand. This is why aggression and pot control is so important. People usually think avoiding multiway pots is important because of all those "damn calling stations". They figure one of them is "bound to catch". While there is certainly some truth to this (your reverse implied odds definitely become more unfavorable as more draw hands enter the pot), it's not the primary reason for you to try to keep them out. The primary reason is that the hand is easier to play and control post flop when there are fewer players battling for the pot. You're much more likely to get paid off by hands like KT or even 99 on a T85 flop with two hearts than you are if there were 5 players in there. If there's action in a 5 way pot, hands like KT and 99 are folding, but those are the hands you want to be up against. You don't want to be up against hands like J9 or A2hh on this board, and you certainly don't want to be up against J9, 67, AT, and A2hh all in the same hand. If you often find yourself thinking you're the most unlucky player on the planet and that somehow people always seem to draw out on you with these hands, then you're probably not raising enough pre flop.
That said, and as I mentioned earlier, you do have other options for playing this hand profitably depending on how your opponents play. If they are mostly passive post flop, playing their hands straight forwardly, then you can afford to let more players into hand, raising closer to the $45 mark than the $68 one. It really depends on their skill level and aggression levels. Another option is if you have one or two players behind you that are prone to stealing in big pots like this pre flop and who will try to steal post flop as well, then you can limp behind here setting a juicy trap that players like that often have a difficult time not falling into (especially if the initial raiser is prone to folding their raised hands to a large reraise). When this happens, you're in a great spot obviously, and it's without question your best scenario of all the betting lines on offer. The key is figuring out how often it will work, because if it doesn't work often enough, then you're better off just reraising to $60+. If this is the line you want to take though, be sure to pay attention to stack sizes, as skilled opponents with deep stacks may take advantage of the opportunity as well, and will often put you in tough spots post flop forcing you to lay down the best hand. Your ideal scenario with this approach is for you to limp behind with another player limping after you and then someone trying to get cute with hands like AQ/88/98s/JTo on the button or cutoff with a big raise. If they were to make a pot sized raise in this spot with 4 players in, they'd have to make it $100 ($16*3 + $16 + $16 + $16 + $3 + $1). Then when the action comes around to you, you can either flat their 3-bet, keeping your hand disguised or make a nice sized check-raise 4 bet depending on how deep the raiser is and how likely they are to bluff post flop. If they are pretty deep, I'd go for the big raise almost every time. However, if they're a bit shorter - say $300 or less behind, then you'll have a better chance of stacking them by letting them feel like they're in control of the hand since they'll have $200 behind in a pot that has $252 in it on the flop. Also worth noting, is that you're almost never folding this hand post flop in this scenario. If there is any possibility of you folding the hand post flop, then you need to take the check raise 4-bet line pre flop instead.
Good players mix up their play, better players mix it up for the right reasons in the right spots against the right opponents, and the best players are orchestrators. Figure out what your opponents' biggest leaks are, and exploit them in the right spots. If you're not at a point in your game where you're comfortable with all the game theory involved or metagaming concepts mentioned above, or if you just find yourself thinking people like me are talking straight out of our asses, then you need to stick to ABC poker and just reraise to $60+ in this spot 100% of the time.
Remember that with KK, you need to be in control of the hand post flop. You don't want to be guessing where you're at in the hand, crossing your fingers the whole way through. That's how you lose big pots.