How Much Should a ReRaise Be?

Please excuse what to some will be a silly question, but how much to reraise by confuses me. I have seen advice to raise by the amount of the pot and 3-4 times the initial raise, but this confuses me for the following reasons:

Reraise by the size of the pot - does this mean that I bet in total the pot size, or should it be the amount to call, and in addition the size of the pot (and is this the pot size before my call or after it)?

Reraise 3-4 the initial raise - again do I bet 3-4 times the raise or 3-4 times the raise plus the initial raise? Also, this seems a dubious guideline because the resulting pot odds that I will give will depend on the initial raise.

I'd appreciate comments on the above, and especially I'd appreciate any simple rules of thumb that could be applied, for a) with no draws possible b) with draws possible. I have searched online but the advice I find is dependent on me understanding the definition of a pot size rise (see above).

Not silly at all and the answer, as always, is... it depends. It depends on what it is you're trying to accomplish and how you expect the OR (original raiser) to react. Lets deal with one very common scenario. You're in late position at a $100.00 table with AK or AQ and a tight player in EP (early position) open raises to 3xBB ($3). I would re-raise either of these hands (although I feel alot better about the AK) simply to define my hand and make any post flop play decisions that much easier. I know this is a how much thread, not a why thread, but the 2 are tied together. I want my raise to accomplish 2 things.
1) AK/AQ is a good hand, but also a vulnerable one. I want to bet enough to discourage anyone behind me, mostly the blinds, to call with speculative hands. and
2) To (as I said before) to define my hand. I'd be perfectly happy to win the hand PF, but I don't actually expect him to fold. By reraising, you are sending a message to the OR that your hand is as good or better than what he raised with. If he's a decent player, and if he sees you to be a decent player, he will have to respect your aggression. In most cases he'll call but unless he connects with the flop, he'll check to you in which case you must follow with a CB.

So how much to raise? I like a slightly bigger than pot sized bet, say $6. This should keep the blinds out of the action, and put marginal pressure on the OR. He'll have to call $3 to win $6. You don't know exactly what he has, but any pair should call and any AJ or weaker should fold. The fact that you reraised will make life alot easier for you and when you're beat, you'll actually lose less by having a clearer undertanding of your own relative hand strength.

The amount should vary based on your holdings, what you put the initial raiser on, and what your table image has been over the session. A min-reraise almost never makes sense, though I see people do it all the time with AA/KK, trying to get value. Not only do you telegraph your hand, but you give the raiser excellent odds to call and try to outflop you. While you should mix up your play, you can't go all that wrong making all your reraises 3-4 times the size of the initial raise. If you are seen doing this with high pairs, A-x suited, maybe even a random connector or two, you will keep your opponents guessing. The biggest mistake you can make is to reraise a set amount (say 5x) with AK, but only 2x with KK/AA. So either keep all your raises/reraises the same, or constantly changing, both in efforts to disguise your hand.

I'm usually 3betting 3-3.5x the current bet. So in a NL25 hand if someone raises to $1 and I decide to 3bet I'll usually make it ~$3.50 to go.

oops, didn't mean to send the first one. lol. It depends a lot on who is the first raiser. If he plays almost every hand and you don't, or if he or she is a tight player and you are not.
I myself like to set a tight aggressive image. I don't like to bluff all that much. It also depends on whether or not you want him to stay in the hand AA, or fold preflop TT or less. If the blinds are high enough you might want him to fold preflop and take it down.
If you don't bet enough, 33 will call and if he hits a 3 and you hit a pair of aces. you might be in big trouble.
This is one of the hardest things that I have to deal with as well.
Good luck

Don't forget that your three bet size is also really contingent on STACK sizes as well. For example, if you are putting in a huge % of your or your opponent's stack with a 3x initial raise re-raise, then you might be better off just shoving.

PLAN the hand: you want your remaining stack size(s) to play well on additional streets (don't get stop-n-go-ed, for instance).

Three betting and 4 betting depends on position and stack sizes. I would say a three bet in position should be 3x the orignal raise. And oop i would make it closer to 4x. 4 betting is a little trickier, but pm me if you want an answer on that, and please include a situation and stats on villain you're playing and stats on yourself.