You know that if you call (the first part of pot odds) you will get 2:1 on your money.
You've calculated your outs, 12 x 4 gives you a 48% chance to win before the turn, 24% after the turn.
Take the 24%, you are a 4 to 1 dog, so you need to be getting at least 4 to 1 on your money to make a correct call, if you are playing strictly by pot odds. And in this example, if it costs you 50,000 to win 100,000, you are only getting 2 to 1 on your money, and you should fold.
Take the number after dividing by 100 and if that number is (or lower than) the amount you will get on your money, you call. If it it is higher, you fold.
This is the basic foundation of how to play. Play only by this, and you will win, in the long run.