It estimates the expected value (average profit/loss) for a wager given your win probability and the quoted odds. Choose between moneyline odds (e.g., -110) or prediction‑market odds (e.g., 0.60 for 60%).

For moneyline odds, we convert to payout per $1 staked: payout = 1 + (100/odds) for plus odds and payout = 1 + (100/|odds|) for minus odds. For prediction‑market odds priced p in dollars, the payout is 1 with cost p. EV = prob × profit_if_win − (1 − prob) × stake.

This simple EV ignores platform fees by default. If you want fee‑adjusted EV for prediction markets, first use the Market Fees calculator to estimate fees and adjust your price or stake accordingly.