European roulette simulator

European roulette odds for every bet

A European wheel has 37 pockets: 1 to 36 plus a single green zero. Every bet pays as if the zero did not exist. A straight number covers 1 of 37 pockets and pays 35:1, so the fair payout would be 36:1. That gap is the house edge.

The formula is the same for every bet: RTP = (pays + 1) × (numbers covered ÷ 37). Red covers 18 pockets and pays 1:1, so RTP = 2 × 18/37 = 97.30%. A dozen covers 12 and pays 2:1, so RTP = 3 × 12/37 = 97.30%. A straight-up number: 36 × 1/37 = 97.30%.

• Straight number: 35:1, win chance 2.70%
• Dozen or column: 2:1, win chance 32.43%
• Red/black, odd/even, 1–18/19–36: 1:1, win chance 48.65%
• House edge on every bet: 1/37 = 2.70%

Why the bet you choose does not change the edge

Because every European bet returns 97.30%, mixing bets only changes volatility. A straight number swings hard: you lose 36 spins in 37 on average and then win 35 units. Red or black is smooth: you win almost half the time. Over thousands of spins both lose about 2.7 units per 100 staked.

American roulette adds a double zero, which drops the RTP to 94.74% (36/38). Always pick the single-zero table when a casino offers both. French tables with la partage return half of an even-money bet on zero, which lifts those bets to 98.65%.

Hot and cold numbers are noise

Each spin is independent. After 500 spins every number is expected to hit about 13.5 times, with a standard deviation of roughly 3.6, so seeing one number at 22 and another at 6 is normal. The simulator lists hot and cold numbers so you can watch them reshuffle with every batch. A number that ran hot has the same 1 in 37 chance on the next spin.

What actually lowers your cost

No betting system beats a fixed 2.70% edge. Martingale, Fibonacci and D'Alembert change the shape of your results, not their average. The only lever is cash back: rakeback returns part of the edge on every wager. At Duel's 50% rate the effective edge on European roulette falls to about 1.35%.

How to use the roulette simulator

Pick a chip value, click the spots you want on the table and press Spin. Bets stay in place, so you can repeat the same layout or add chips between spins. Spin ×500 runs instantly and adds every result to the stats, so you can compare observed RTP with the theoretical 97.30% and watch the gap shrink as the spin count grows.