Pokerstove is very usefull tool for online players, but when you play live you simply can't use it. Does exist (even aproximate) an algorithm in order to estimate your equity against the range of your opponent in live poker? Namely an algorithm that can I run in my head to calculate the equity.
At every stage in the game there are different guidelines, the weaker your starting hands the more tough decisions you'll face later in the hand.
If you enter the hand with a good holding, you'll have a pretty easy decision to make on the flop if you come up against stiff resistance from your opponents. If you have a made hand you can play it strongly, if you have a draw you could play it weakly and if you miss the flop completely you can go home.
The problems arise when you have a made hand that's not the nuts, and your opponent is playing very aggressively. You will always fear he has the nuts and you're beat. The issue is not what is the a priori probability your opponent has a better hand than you. The question is: given the information you have on your opponent's playing style, would he play that aggressively without the nuts ? Is he even representing the nuts, or is he a poor player who's just excited he has bottom pair ?
The first question you have to answer is: does you opponent think he has the better hand ? If the answer is, no regardless of what two cards you have, you can raise big because he thinks he has the worse hand and will fold in a second.
The second question you have to ask yourself is: given that your opponent thinks he has the best hand, knowing your hand do you also think he has the best hand or do you think your hand is better ? If you think your hand is better, raise big for value and you'll get called. If you think he has the best hand, fold. You're not going to bluff him out of the hand.
In conclusion, it is not so important to know the actual equity you have. What is important is the ability to answer those two questions.
There's the rule of 2 and 4 to get a good idea how likely it is, that a hand improves after the flop. You need to be able to calculate the cards that will help your hand or your opponents hand if you assume he is on a draw, a combodraw or a weak pair and a draw for this though:
When you say equity you automatically say equity against something, where something can be either a hand or, more likely, a range. On the other hand, the good part is that you don't need to calculate the equity to the last decimal. If you determinate your equity being 60% and your real equity is 65% nothing wrong is going to happen (not that I know of).
Calculating (or guesstimating) equity can be improved greatly away from the table. You You cannot use PokerStove at a live table, but there are a few shortcuts:
Hope my answer helps!