Roulette is one of the simplest casino games — and one of the easiest to misunderstand. The math is fixed by the wheel type: European, American, or French. No betting pattern changes the house edge, but understanding the numbers helps you choose the better wheel, size your bets realistically, and estimate how long your bankroll may last.
This page is the central hub for our roulette calculators, guides, and bankroll tools. Use it to find the right tool for your specific question.
Roulette Calculators — Choose the Right Tool
- Bet Coverage Calculator — Use when you want to know how much of the wheel your combined bets cover, your true win probability, and the expected value per spin.
- Martingale Simulator — Use when you want to test Martingale or other progression systems and see how bankroll pressure builds over time.
- Session Budget Calculator — Use when you want to estimate how long a roulette budget may last on average at your chosen stake size.
- Loss Limit Calculator — Use when you want to set a stop-loss for your roulette session and see how it protects your bankroll across multiple sessions.
- Gambler’s Ruin Calculator — Use when you want to model the probability of hitting a target or going broke over a sequence of even-money bets.
- Casino Game Cost Calculator — Use when you want to compare roulette against other casino games on expected hourly cost at the same bet size.
Roulette Quick Reference
House Edge by Wheel Type
| Wheel | Zeros | House Edge | Numbers |
|---|---|---|---|
| French (La Partage) | Single 0 | 1.35% (even-money bets) | 37 |
| European | Single 0 | 2.70% | 37 |
| American | 0 and 00 | 5.26% | 38 |
The extra zero on the American wheel nearly doubles the house edge without improving payouts. If both versions are available, European is mathematically better. French Roulette with La Partage or En Prison is better still on even-money bets.
Common Bet Payouts (European Wheel)
| Bet Type | Payout | Probability | Coverage |
|---|---|---|---|
| Straight Up (1 number) | 35:1 | 2.70% | 1/37 |
| Split (2 numbers) | 17:1 | 5.41% | 2/37 |
| Street (3 numbers) | 11:1 | 8.11% | 3/37 |
| Corner (4 numbers) | 8:1 | 10.81% | 4/37 |
| Six Line (6 numbers) | 5:1 | 16.22% | 6/37 |
| Dozen / Column (12) | 2:1 | 32.43% | 12/37 |
| Even-Money (Red/Black, Odd/Even) | 1:1 | 48.65% | 18/37 |
Every bet on a standard European wheel has the same house edge: 2.70%. The payout structure is designed so that no bet type is better or worse than another — they all have identical expected value per dollar wagered. The only exception is French Roulette with La Partage, where even-money bets drop to 1.35%.
Common Roulette Myths
- “Red is due after 10 Blacks.” No. Each spin is independent. Previous outcomes do not change the probability of the next spin. The chance of Red is 18/37 every time.
- “Betting systems beat the house.” No. Martingale, D’Alembert, Fibonacci, and Labouchère change the distribution of outcomes (many small wins vs. rare large losses), but they do not change the expected value. Long-run cost is always: Total Wagered × House Edge.
- “Some numbers hit more often.” Not on a fair wheel or fair RNG. Every number has the same probability on a properly functioning game. Tracking physical wheels for mechanical bias is a different discipline (advantage play) and does not apply to online roulette.
Related: House Edge Comparison (All Casino Games) | The Math of the Martingale Strategy