Use transparent manual inputs to calculate odds, probability, expected value, payout, bankroll exposure, and portfolio risk.
A parlay combines multiple selections into one calculation. Decimal odds are multiplied to estimate the combined price, while the stake is multiplied by that price to estimate payout. The probability field is separate: it reflects your assumptions and is multiplied across legs only as a simple independence estimate.
Open calculatorExpected value compares the probability you assign to an outcome with the return offered by the odds. A positive result means the assumptions produce a theoretical long-run gain per modeled stake; it does not predict whether one event will win.
Open calculatorImplied probability converts an odds quote into the break-even win rate before accounting for bookmaker margin. The calculator normalizes American and fractional inputs into decimal odds and then applies one divided by decimal odds.
Open calculatorThe calculator converts every outcome price into implied probability, adds those probabilities to measure overround, and then divides each probability by the total. The normalized values sum to 100% and provide a simple market-based fair probability estimate.
Open calculatorThe calculator shows a fixed unit size and a Kelly-based stake. Kelly sizing uses odds and estimated probability to find a theoretical growth-maximizing fraction; half-Kelly reduces that exposure to account for estimation error and volatility.
Open calculatorThe optimizer creates candidate two-leg and three-leg simulations from manually entered odds and probabilities. It applies confidence adjustments, market-type weights, same-event correlation penalties, probability floors, long-shot limits, and fractional-Kelly caps before allocating the selected budget.
Open calculatorA binary event contract settles at a fixed value when the selected outcome occurs and at zero when it does not. The calculator compares contract cost, fees, settlement value, budget, and your probability estimate to show break-even probability, maximum profit, maximum loss, and expected value.
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