Roulette House Edge
The house edge is not a fee, a commission or a rake. It is the gap between what a bet pays and what it is worth, and in roulette that gap can be calculated exactly from two numbers: the pocket count and the paytable.
From first principles
Bet one unit straight up on 17 at a European table. There are 37 pockets, so you win once in 37 attempts. When you win, the table pays 35 to 1 and returns your unit, so you receive 36.
Over 37 spins you stake 37 units and receive 36. You are down one unit on 37 staked:
1 ÷ 37 = 0.027027 = 2.70%
That is the entire derivation. Everything else about roulette maths is this calculation in different clothes.
Formally, expected value per unit staked is P(win) × payout − P(lose) × 1. For a straight-up bet on a European wheel: (1/37) × 35 − (36/37) × 1 = −1/37. Negative, small, and unavoidable.
Why every bet costs the same
Roulette payouts are all derived from a single rule: a bet covering k numbers pays 36 ÷ k − 1 to 1. A street covers three and pays 11. A dozen covers twelve and pays 2. Red covers eighteen and pays 1.
Substitute that into the expected-return formula and the k cancels:
RTP = (payout + 1) × k ÷ N = (36 ÷ k) × k ÷ N = 36 ÷ N
The result depends only on N, the pocket count. Not on which bet, not on how many chips, not on how they are arranged. That is why a straight-up bet and a red bet cost identically, and why building a wide board in the payout calculator never moves the edge figure.
| Wheel | Pockets (N) | Payout base | RTP | House edge |
|---|---|---|---|---|
| European / French inside | 37 | 36 | 97.30% | 2.70% |
| French even-money (la partage) | 37 | 36 + half-back | 98.65% | 1.35% |
| American | 38 | 36 | 94.74% | 5.26% |
| American five-number bet | 38 | 35 | 92.11% | 7.89% |
| Mini (0–12) inside | 13 | 12 | 92.31% | 7.69% |
The five-number bet is the only exception to the rule. Covering five numbers should pay 36 ÷ 5 − 1 = 6.2 to 1; the table pays 6. That extra rounding is worth 2.63% and makes it the worst bet in roulette.
The edge applies to turnover, not to your deposit
This is the single most misunderstood point in casino maths, and it is where the money actually goes.
Deposit $200 and play $10 spins for an hour at 50 spins per hour. You have staked $500 — not $200 — because winnings are re-staked. The expected loss is one thirty-seventh of $500, or $13.51. Play two hours and you have staked $1,000 and expect to lose $27.03, even though you only ever put $200 on the table.
Turnover accumulates far faster than people expect, and it is why "I only ever deposit $100" is not a description of what a habit costs. Someone recycling $100 forty times has staked $4,000.
| Bet per spin | 50 spins | Turnover | Expected loss | American equivalent |
|---|---|---|---|---|
| $1 | 50 | $50 | $1.35 | $2.63 |
| $5 | 50 | $250 | $6.76 | $13.16 |
| $10 | 50 | $500 | $13.51 | $26.32 |
| $25 | 50 | $1,250 | $33.78 | $65.79 |
| $50 | 50 | $2,500 | $67.57 | $131.58 |
| $100 | 50 | $5,000 | $135.14 | $263.16 |
Cost per hour is the figure that matters
Because expected loss scales with turnover, and turnover scales with pace, the useful unit is dollars per hour. It is directly comparable to other entertainment, and it makes the effect of speed obvious.
| Pace | Typical of | Turnover/hour at $10 | European cost/hour | American cost/hour |
|---|---|---|---|---|
| 30 spins/hour | Busy live table | $300 | $8.11 | $15.79 |
| 50 spins/hour | Quiet live table | $500 | $13.51 | $26.32 |
| 90 spins/hour | Online live dealer | $900 | $24.32 | $47.37 |
| 250 spins/hour | RNG roulette, manual | $2,500 | $67.57 | $131.58 |
| 600 spins/hour | RNG with auto-play | $6,000 | $162.16 | $315.79 |
The bottom row is why auto-play is the most expensive button in an online casino. The odds are unchanged; they are simply applied twenty times as often. Your own figures go in the session cost calculator.
House edge, RTP and volatility are three different things
House edge is the share of each stake the operator keeps over the long run. 2.70% on a European wheel.
RTP — return to player — is the mirror image: 100% − house edge. A 97.30% RTP and a 2.70% edge are the same statement. Slots are usually described in RTP because 96% sounds better than 4%.
Volatility is how far individual results scatter around the average, and it is independent of the edge. A straight-up bet and a red bet on the same wheel have the same edge and completely different volatility: one wins 2.7% of the time for 35 units, the other 48.65% of the time for one. Systems and bet selection move volatility. Nothing but the wheel moves the edge.
Why the distinction matters. Short sessions are dominated by volatility, so they frequently end in profit. Long sessions are dominated by the edge, so they converge on a loss. This is the opposite of investing, where a positive expected return makes time an ally. In a negative-expectation game, the mathematically optimal session length is the shortest one that still gives you what you came for. The bankroll calculator shows the crossover.
The four ways to reduce it
- Play a single-zero wheel. 2.70% instead of 5.26% — the largest single decision available, worth more than everything else on this list combined.
- Find la partage. 1.35% on even-money bets. Free, if the table offers it.
- Slow down. Halving spins per hour halves cost per hour exactly. Nothing else has that property.
- Claim rakeback. A rebate on turnover reduces the effective edge directly, with no wagering requirement. Roulette contributes only 10–20% toward most deposit-bonus wagering, so rakeback is usually the better offer for a roulette player. Quantify it in the rakeback calculator.
Not on the list: bet selection, betting systems, pattern reading, and anything involving the scoreboard. Those change the shape of the outcome, and the shape is not the price.
House edge FAQ
What is the house edge in roulette?
2.70% on a European single-zero wheel, 5.26% on an American double-zero wheel, and 1.35% on even-money bets at a French table with la partage. Mini Roulette is 7.69% on inside bets and the American five-number bet is 7.89%.
Why is the house edge the same for every roulette bet?
Because all payouts are derived from the same formula — a bet covering k numbers pays 36/k − 1. When you compute expected return, the k cancels out and only the pocket count remains. The edge is therefore 36/37 on European and 36/38 on American, regardless of the bet.
Does the house edge mean I will definitely lose?
Not in a single session. Short-run results are dominated by variance and frequently end in profit. Over enough spins the average converges on the expected value, and the expected value is negative. The longer you play, the more certain the outcome becomes.
What is the difference between house edge and RTP?
They are the same number stated two ways: RTP = 100% − house edge. A 2.70% edge is a 97.30% RTP. Casinos tend to quote RTP because a large number sounds more appealing than a small one.
How much does roulette cost per hour?
At $10 a spin and 50 spins an hour, about $13.51 on a European wheel and $26.32 on American. With auto-play at 600 spins an hour the same stake costs $162 and $316 respectively — same odds, applied far more often.
Can the house edge ever be beaten?
Not through betting patterns. Historically it has been beaten by exploiting physically defective wheels or by timing the ball, both of which require a specific physical wheel and thousands of observations, and neither of which works against an RNG or a live-streamed table. Rakeback and rebates reduce the effective edge but do not reverse it.
GETRAKEBACK. 18+.
Other guides
- Roulette Rules — How a round works, every bet on the table, and the rules that change the maths.
- Roulette Odds & Payouts — The full payout and probability table for every wheel, side by side.
- Roulette Strategies — Ten systems, what each actually does to your distribution, and why none change the edge.
- Roulette Wheel Layout — Pocket order, wheel sectors, the racetrack and why the numbers sit where they do.
- European vs American Roulette — One extra pocket, double the cost. The comparison in full.
18+. Roulette has a fixed house edge, so over enough spins the maths favours the operator — always. If you play for real, treat it as money spent on entertainment, set a limit before you start and stop when you reach it. Our responsible gambling page covers the warning signs and where to get free, confidential help.