Roulette Payout Calculator

Roulette calculations rely on fundamental probability and payout ratios determined by the design of the wheel. European roulette features 37 pockets (0 through 36), while American roulette features 38 pockets (0, 00, and 1 through 36). The probability of winning ($prob$) for a specific bet is calculated by dividing the number of winning pockets matching your bet type ($betType$) by the total number of pockets on the roulette wheel ($rouletteType$). Expressed as a percentage, the win probability ($probPer$) is simply $prob \times 100$. The cash payout ($payout$) is determined by the formula: $payout = ((36 - betType) / betType) \times amount$. Finally, the expected return ($expectedReturn$), which accounts for both winning and losing scenarios over time, is computed as: $expectedReturn = (payout \times prob) - (amount \times (1 - prob))$.

Imagine you place a $10 straight-up bet on a single number (such as the number 17) on a European roulette wheel. Here, your stake amount is 10, the bet covers 1 number ($betType = 1$), and the wheel has 37 total pockets ($rouletteType = 37$). First, we find the winning probability: $prob = 1 / 37 \approx 0.02703$ (or about 2.70%). Next, we calculate your potential cash payout if you win: $payout = ((36 - 1) / 1) \times 10 = 35 \times 10 = $350$. Finally, to understand the long-term mathematical value of this wager, we compute the expected return: $expectedReturn = (350 \times 0.02703) - (10 \times (1 - 0.02703)) = 9.46 - 9.73 = -0.27$. This means on average, for every $10 bet on a single number, you can statistically expect to lose about 27 cents due to the single zero house edge.

When analyzing roulette odds, always check whether you are playing on a European or American wheel, as the extra double-zero pocket dramatically shifts the house edge from 2.70% to 5.26%. Understand that short-term wins can defy statistical averages, but the house edge ensures that the casino maintains a mathematical advantage over extended play. Use this calculator to experiment with outside bets (like red/black or odd/even) versus inside bets (like straight-ups or splits) to see how variance and payout multipliers alter your risk profile.