House edge is the average loss on a bet, expressed as a percentage of the stake. On single-zero roulette it is 2.70%: over a very large number of spins, the game keeps about £2.70 of every £100 staked. It varies by game and by bet, from about 1% on some baccarat bets to over 14% on the baccarat tie bet. It is an average, not a per-session prediction.
On this page
What house edge means
House edge is the built-in mathematical advantage a casino game has over the player. Wizard of Odds defines it as the ratio of the average loss to the initial bet1.
A house edge of 2.70% means that, over a very large number of bets, players lose on average £2.70 for every £100 staked. It does not mean each bet loses 2.70%; each bet either wins or loses. The percentage describes the long-run average.
House edge is the mirror image of RTP. For a game with one fixed return, house edge is 100% minus RTP. Our RTP guide covers that side of the calculation.
How house edge is calculated
House edge comes from comparing what a bet pays with the true odds of winning it. Roulette shows this clearly, and the calculation below can be checked by anyone.
Single-zero roulette
A single-zero wheel has 37 pockets: numbers 1 to 36 and one zero. A bet on a single number pays 35 to 12.
Imagine placing a £1 bet on every one of the 37 pockets over 37 perfectly average spins:
- You win once, collecting £35 profit.
- You lose 36 times, losing £36.
- Net result: −£1 over 37 bets, or −1/37 per bet.
One divided by 37 is 2.70%, which matches the published house edge for single-zero roulette2.
Double-zero roulette
A double-zero wheel has 38 pockets. The same bet still pays 35 to 1, so the net result is −£2 over 38 bets: 2/38, or 5.26%2.
The payout did not change. Adding one extra pocket nearly doubled the edge.
Typical house edge by game
The table lists figures that are either published by Wizard of Odds or, where marked, derived directly from the game's rules. Rules vary between versions, so always check the rules of the specific game.
| Game and bet | House edge | Basis |
|---|---|---|
| Single-zero roulette, any standard bet | 2.70% | Derived: 1/372 |
| Single-zero roulette, even-money bets with la partage | about 1.35% | Derived: half the stake returned on zero2 |
| Double-zero roulette, most bets | 5.26% | Derived: 2/382 |
| Double-zero roulette, 0-00-1-2-3 bet | 7.89% | Published2 |
| Baccarat, banker bet (5% commission, 8 decks) | 1.06% | Published3 |
| Baccarat, player bet (8 decks) | 1.24% | Published3 |
| Baccarat, tie bet paying 8 to 1 (8 decks) | 14.36% | Published3 |
| Craps, pass or come | 1.41% | Published1 |
| Craps, don't pass or don't come | 1.36% | Published1 |
| Blackjack, liberal rules with optimal strategy | 0.28% | Published; rises with less favourable rules or strategy errors1 |
| Slots | 100% minus the RTP of the version in use | Derived from RTP |
Two points stand out. First, the same table can offer bets with very different edges: the baccarat tie bet carries more than ten times the edge of the banker bet. Second, figures for skill-influenced games such as blackjack assume optimal decisions1.
From house edge to expected cost
House edge becomes more useful when it is converted into money. The formula is:
Expected loss = total amount staked × house edge
"Total amount staked" means turnover: every stake, including winnings that are bet again4. This is why a small edge can still cost a meaningful amount over a long session.
Worked example (hypothetical)
The stakes below are invented to show the arithmetic.
| Scenario | Turnover | House edge | Expected loss |
|---|---|---|---|
| 200 bets of £5 on single-zero roulette | £1,000 | 2.70% | £27.03 |
| 200 bets of £5 on double-zero roulette | £1,000 | 5.26% | £52.63 |
| 100 bets of £10 on the baccarat banker bet | £1,000 | 1.06% | £10.60 |
| 100 bets of £10 on the baccarat tie bet | £1,000 | 14.36% | £143.60 |
These are averages across a huge number of identical sessions. Any one session could lose far more or finish ahead.
Rule changes move the edge
Because house edge comes from comparing payouts with true odds, any change to either side changes the figure.
- Extra zeros. Adding a second zero to roulette raises the edge on most bets from 2.70% to 5.26%2.
- Returning part of a losing stake. Under la partage, even-money bets lose only half the stake when the ball lands on zero, bringing the edge on those bets to about 1.35%2.
- Different payouts on the same event. In Evolution's Lightning Roulette, straight-up bets that are not given a multiplier pay 29 to 1, while between one and five randomly selected numbers receive multiplied payouts of 50x to 500x5. Standard roulette pays 35 to 1 on the same bet2. Calculating the edge of that bet requires the probability of each multiplier, so the figure to check is the RTP given in the game's own rules.
The practical lesson is that a game's name does not tell you its edge. Its rules do.
House edge is not the same as hold
The two terms are often confused. House edge is a mathematical property of a bet. Hold percentage is the ratio of chips a casino keeps to the total chips sold over a period1.
Because hold is measured against chips bought rather than the total amount bet, it reflects player behaviour, such as how often winnings are bet again. It is therefore usually a different number from the house edge.
Regulators use a related measure. The Gambling Commission describes gross gaming yield as turnover minus wins4.
What house edge does not tell you
- It does not predict a session. Like RTP, it is an average achieved over a very large number of plays6.
- It cannot be removed by a betting system. Every bet in the table carries its own negative expected value. Changing stake sizes or sequences changes how much money is exposed to the edge, not the edge itself.
- It is not the only cost. Faster games mean more bets per hour, so turnover and expected loss both rise.
Gambling involves financial risk, and the house edge is the reason. If you are concerned about your gambling, see our responsible gambling page.
- House edge
- The average loss on a bet expressed as a percentage of the stake, representing the casino's built-in mathematical advantage. For a game with a fixed return, house edge equals 100% minus RTP.
- Hold percentage
- The share of chips or money a casino keeps compared with the chips sold or money put into play over a period. Unlike house edge, it reflects player behaviour, such as how often winnings are bet again.
- RTP
- RTP (return to player) is the percentage of all money staked on a game that it is designed to pay back as winnings, averaged over a very large number of plays. It does not predict the result of any single session.
- Side bet
- An optional extra wager placed alongside the main bet in a table game, with its own payouts and its own house edge.