What Is Poker EV?
Expected value (EV) is the average amount you can expect to win or lose on a given decision if you made it many times over. A positive EV (+EV) means the play is profitable in the long run, while a negative EV (-EV) means it loses money. Strong poker players make decisions based on EV rather than the outcome of any single hand.
How to Use This Calculator
Enter three numbers: your estimated probability of winning the hand (as a percentage), the amount of money you stand to win if you win, and the amount you stand to lose if you lose. The calculator multiplies each outcome by its probability and combines them into a single EV figure. The amount won is usually the current pot plus opponents' future bets; the amount lost is the chips you have to put in to continue.
The Formula Explained
The model uses $$\text{EV} = p_{\text{win}} \times W - (1 - p_{\text{win}}) \times L$$ Here \(p_{\text{win}}\) is your win probability, \(W\) is the amount won and \(L\) is the amount lost. The term \((1 - p_{\text{win}})\) is simply the lose probability. Because exactly one of the two outcomes happens, the probabilities sum to one, so this is a complete two-outcome expectation.
Worked Example
Suppose you have a flush draw and estimate a 35% chance to win. The pot already offers you $120 if you win, and a call costs you $40 if you lose. $$\text{EV} = 0.35 \times 120 - 0.65 \times 40 = 42 - 26 = \textbf{+\$16}$$ Since the EV is positive, calling is the profitable play over the long run.
FAQ
What does a positive EV mean? It means the decision earns money on average if repeated many times — it is the mathematically correct play.
How do I estimate win probability? Use your equity against your opponent's likely range; pot odds and equity calculators can help. Outs \(\times\) ~2 per remaining card is a quick shortcut.
Does EV guarantee I win this hand? No. EV describes long-run averages. You can make a +EV decision and still lose a specific hand due to variance.
