Roulette Odds Calculator
For custom bets, enter your own covered numbers and payout ratio.
How to use this roulette odds calculator
This calculator helps you quickly estimate your chance of winning in roulette and your expected result over many spins. Choose a wheel type, select a bet, and enter your stake. The tool returns:
- Single-spin win probability
- Single-spin loss probability
- House edge for the selected setup
- Expected value per spin
- Expected total result over multiple spins
- Chance of at least one win in your session
European vs American roulette odds
The biggest difference between roulette games is the wheel itself. European roulette has 37 pockets (0 to 36), while American roulette has 38 pockets (0, 00, and 1 to 36). That extra 00 increases the house edge.
For most standard bets, the built-in payout does not fully match true odds, which is why casinos keep an advantage. In practical terms, your expected loss per $100 wagered is usually:
- European roulette: about $2.70
- American roulette: about $5.26
Quick odds reference (single spin)
| Bet Type | Numbers Covered | Payout | Win % (European) | Win % (American) |
|---|---|---|---|---|
| Straight Up | 1 | 35:1 | 2.70% | 2.63% |
| Split | 2 | 17:1 | 5.41% | 5.26% |
| Street | 3 | 11:1 | 8.11% | 7.89% |
| Corner | 4 | 8:1 | 10.81% | 10.53% |
| Six Line | 6 | 5:1 | 16.22% | 15.79% |
| Dozen / Column | 12 | 2:1 | 32.43% | 31.58% |
| Even Money | 18 | 1:1 | 48.65% | 47.37% |
Why expected value matters more than streaks
Roulette can produce short-term hot streaks and cold streaks, but expected value (EV) describes the long-term average. If EV is negative, repeated play tends to move your results downward over time, even if you win in the short run.
Simple interpretation
- If EV per spin is -$0.27 on a $10 bet, your long-term average loss is $0.27 per spin.
- Over 100 spins, the expected total would be around -$27.
- Actual outcomes may be much higher or lower because of variance.
Bankroll and session planning tips
This tool can support better decision-making before you play. Try different bet sizes and session lengths to see how expected losses scale.
- Set a fixed bankroll before betting
- Use smaller unit sizes if you want longer play time
- Prefer European wheels when available
- Avoid chasing losses after a bad run
- Stop when your preset limit is reached
Frequently asked questions
Can any roulette strategy beat the house edge?
Betting systems can change variance and session experience, but they do not remove the built-in edge of the wheel. Over enough spins, expected value dominates.
Are outside bets safer than inside bets?
Outside bets (like red/black) usually win more often, but they also pay less. On the same wheel type, standard bets generally carry the same house edge.
Is this calculator useful for custom bets?
Yes. Choose Custom Bet and enter how many numbers your bet covers and the payout ratio. The calculator then estimates probability and expected value automatically.
Responsible gambling note: this page is educational. Never bet money you cannot afford to lose.