Originally Posted by 10058765
If you mean software, I'd say Pokerstove (free).
If you have money to spend you could consider a tracker.
Hopefully I can plug this as well, but the free equity calculator in ace poker drills. It's way better than poker stove. Many more features, it can auto calculate ranges, set and save pre-loaded ranges, drag and paint ranges, etc...
I used poker stove for a lot of years, and got frustrated at the lack of options, so check it out: Poker equity calculator
Once you get rolling, then you'll need a poker database also.