So I have started playing some live cash game max buyins is around 300 usd
Most people buyin around 90 usd and thats around 200BB.
So I need some help with bet sizing. This live cash game is in Vietnam and is very loose (people dont really fold hands when raising). My stack is 100BB and I wake up in small blind with AA.

UTG limps 40 cent
UTG+1 limps 40 cent
Middle pos raise 3 usd
Middle pos+1 calls 3usd
Hero AA small blind 3bet 15usd

Is my raise here okay? Or should it be bigger in very loose cash games?

What is your guys standard 3bet sizing with premium hands in very loose cash games?

Regards,
BangeN

Nobody can answer really unless they play in your game.
The answer is the highest amount you expect to get called by 1 or 2 opponents.

If you got $15 in pre (1/6 of your stack) called by J9 then I think you are doing fine here.
If you believe he would call $20 with J9 then obviously go for $20 next time.

Your sizing seems good in a vacuum. The pot was about $10 with your call, and you made it $12 more, so a bit over a pot-sized bet. The general rule of thumb is that 3-bets should be about pot-sized.

As the poster above mentions, though, it really depends on what is normal in the game. I used to play in a $1/$1 game that most people bought into for 200BBs and it was common for people to limp and then call an open to $15 with weak hands. In that game, I would make my 3-bets at least 1.5x pot, and still sometimes got more callers than I wanted. Sometimes though, I got no callers at all.

Thanks for the answer. Really interesting strategy to make the 3bets atleast 1.5x pot. Im really new to loose cash games because I mostly been playing MTT
now for 2 years and its so different. In this cash game its very common that the players feel the urge of calling with bad hands when u are 3betting them.
So I noticed the only hands I really can 3bet is a very tight premium hand range because of people always calling the 3bets and making multi way pots.

Oh, yes. There is very little fold equity in these games. You should only be betting/raising for value. The good nes is that they are often so passive that you can get in to the pot cheaply with your speculative hands, and raise your premiums hug, and they never adjust. Even though they know you have a premium, they want to call you to crack it, and then they are undisciplined enough that if they hit anything on the flop you can continue to value-bet and they will call with hands that are way behind. Often though, they will be passive enough that if you have medium value you can get to a cheap showdown.

Bottom line: these games have very big swings, but they are very profitable and the players are very exploitable.