The house edge is the average share of each bet a casino game keeps for the operator over the long run, shown as a percentage of your stake. Single-zero roulette has a house edge of 2.70%, so every £10 bet costs about 27p on average. It's built into the payouts, it applies to every bet, and no betting system removes it.
House edge is the average loss per bet, as a percentage of the stake.
It comes from paying winners less than the true odds.
Expected cost = total amount staked × house edge.
Edges vary hugely: some bets cost under 1.5%, others over 14%.
Betting systems change the size of swings, never the edge.
Definition
Average loss as a share of the stake
Single-zero roulette
2.70%
Double-zero roulette
5.26%
Baccarat Banker bet
1.06%
Same as
100% minus RTP
House edge defined
Wizard of Odds defines the house edge as the ratio of the average loss to the initial bet. Put simply, it's how much of each pound you stake the game expects to keep, averaged over a very long run. For slots the same idea is usually expressed the other way round as RTP: a 96% RTP slot has a 4% house edge.
The edge isn't a fee taken from your balance. It's built into the prizes, which pay slightly less than the true odds of winning. That small gap, repeated across every bet, is how casinos make money. You'll find related maths terms such as volatility in our casino app glossary.
How the house edge is worked out
Casino maths textbooks give a neat formula. If a bet pays x to 1 and the true odds against winning are y to 1, the house edge is (y − x) ÷ (y + 1).
Take a straight-up bet on one number in single-zero roulette. There are 37 pockets, so the true odds against you are 36 to 1, but the bet pays 35 to 1. That gives (36 − 35) ÷ 37 = 1 ÷ 37, about 2.70%. On a double-zero wheel the true odds are 37 to 1 with the same 35 to 1 payout, giving 2 ÷ 38, about 5.26%.
Seen in pounds: a £10 straight-up bet on a single-zero wheel wins £350 with a 1 in 37 chance and loses £10 with a 36 in 37 chance. The expected value is (£350 − £360) ÷ 37, a loss of about 27p per bet.
House edge by casino game
The figures below come from Wizard of Odds' house edge table (opens in a new tab). They assume correct play where strategy matters, and individual game versions can differ, so check the rules screen of the game in your app.
Typical house edge by game and bet
Game or bet
House edge
Expected cost per £100 staked
Video poker, full-pay Jacks or Better
0.46%
46p
Baccarat, Banker
1.06%
£1.06
Baccarat, Player
1.24%
£1.24
Roulette, single zero
2.70%
£2.70
Roulette, double zero
5.26%
£5.26
Baccarat, Tie
14.36%
£14.36
Slots (general range)
2% to 15%
£2 to £15
Keno
25% to 29%
£25 to £29
The spread inside a single game is striking: on a baccarat table, the Tie bet costs more than 13 times as much as Banker. Our guide to the house edge of mobile casino games adds more games, and the European roulette page explains why single-zero wheels cost less.
What the house edge costs per hour on a phone
The edge per bet looks small, but the cost depends on how much you stake in total. A widely used worked example: an average bet of £10, 60 decisions an hour, for three hours, on single-zero roulette is £1,800 staked, and £1,800 × 2.70% = £48.60 of expected loss. Casinos call this the theoretical loss.
UK rules put a ceiling on pace. Online casino games other than slots must allow at least 5 seconds per game cycle, so a digital table can't run more than 3,600 ÷ 5 = 720 rounds an hour. Slots need at least 2.5 seconds per spin, a ceiling of 1,440 spins an hour. Real play is slower, but the arithmetic shows why speed matters: more rounds means more total stake, and more expected cost. Our page on game speed rules has the detail.
House edge myths and betting systems
Because each bet carries the edge, no sequence of bets can turn it into an advantage. Wizard of Odds' review of betting systems (opens in a new tab) found that in a craps simulation, a Martingale player (doubling after each loss) went broke in 19.65% of sessions, and the ratio of money lost to money bet matched flat betting.
Doubling up after losses makes small wins more frequent and big losses faster, and table limits stop the sequence.
Waiting for a number that's due doesn't help, because every spin is independent; see our RNG entry.
Basic strategy in blackjack does reduce the house edge compared with guessing, but it doesn't remove it. Our blackjack strategy on mobile page explains how.
Gambling is entertainment that costs money. Over time, the house edge means losses are likely. If you're trying to win back losses, the National Gambling Helpline (0808 8020 133) is free and open 24/7.
Related terms
RTP: the same figure from the player's side, used mainly for slots.
Side bet: optional extra bets that often carry higher edges.
Payout: what a winning bet pays, which sets the edge against the true odds.
Game cycle: one round, the unit UK speed rules are measured in.
Partner casino apps and the house edge on their offers
Every casino app's games carry a house edge, and our partners' welcome offers are for slots rather than table games, which are often excluded or count for less. If you're comparing, these are the current offers; all are 18+, for new customers, and terms apply.
Coral: between 1 October 2026 and 1 February 2027, deposit (certain types excluded) and bet £10 or more on slots for 100 free spins at 10p on selected games. You have 48 hours to accept and 7 days to use them, and spin winnings have no wagering.
Ladbrokes: deposit and spend £10 or more on slots to get 50 free spins a day for 10 days, to a maximum of 500, at 10p each on selected games. Claim by 23:59 daily; each batch lasts 7 days; no wagering. PayPal, Paysafe, Neteller, Skrill, Moneybookers and prepaid card deposits are excluded.
PlayOJO: first deposit of £10 or more brings 80 free spins on Big Bass Bonanza at 10p each for new UK customers (excluding Northern Ireland), with cash winnings and no wagering. Not combinable; designated offer link only.
Coral and Ladbrokes are run by the same company, LC International Limited (Entain), so you may not be able to open new accounts with both. For table-game apps, see best roulette apps.
Coral and Ladbrokes are both run by LC International Limited (Entain). If you already hold an account with one Entain brand, you may not be able to open another; check the terms first.
Significant terms: 18+. New players only. Offer runs 01/10/2026 to 01/02/2027. Deposit (certain types excluded) and bet £10+ on slot games to get 100 free spins (selected games, £0.10 each, 48 hrs to accept, valid 7 days). No wagering on free spin winnings. Deposits by Neteller, PayPal, Paysafe, Skrill, prepaid cards and certain debit cards do not qualify. Restrictions and T&Cs apply. GamCare.org.uk
Read our Coral app reviewLicence: LC International Limited, Gambling Commission account 54743. Offer checked 5 October 2026.
Time limitClaim daily for 10 days; each batch valid 7 days
Worked valueUp to 500 spins at £0.10 (up to £50 in spins)
Significant terms: 18+. New customers only, from 14/11/25 until further notice. Certain deposit methods excluded. Deposit and spend £10+ on slots for 50 free spins a day during the first 10 days after first deposit and registration (max 500, £0.10 each, selected games, claim before 23:59 each day, valid 7 days). No wagering. Prepaid cards, PayPal, Paysafe, Neteller, Skrill and Moneybookers deposits do not qualify. Restrictions and T&Cs apply. GamCare.org.uk
Read our Ladbrokes app reviewLicence: LC International Limited, Gambling Commission account 54743. Offer checked 5 October 2026.
Significant terms: 18+. New UK customers (excluding Northern Ireland). First deposit only. Minimum deposit £10. 80 free spins on Big Bass Bonanza, £0.10 each. No wagering requirements; winnings paid in cash. Cannot be used with any other offer. Only available to players who arrive through the designated offer link. Full T&Cs apply. GamCare.org.uk
Read our PlayOJO app reviewLicence: Skill On Net Limited, Gambling Commission account 39326. Offer checked 5 October 2026.
18+. Every casino game has a built-in house edge, so over time you should expect to lose what you stake. Set a budget before you play and stop when it’s gone: safer gambling tools and support. Free, confidential help: National Gambling Helpline 0808 8020 133.
Frequently asked questions
What is the house edge in simple terms?
It's the share of each bet a casino game expects to keep over the long run. A 2.70% house edge means that, on average, every £100 staked returns £97.30 and the operator keeps £2.70. It comes from paying winners slightly less than the true odds. In any short session you may win or lose more than that, but the more you stake in total, the closer results tend to get. Our RTP entry shows the same idea from the player's side.
Which casino game has the lowest house edge?
Among the games Wizard of Odds lists, full-pay Jacks or Better video poker has one of the lowest at 0.46%, assuming perfect strategy, followed by baccarat's Banker bet at 1.06%. Pay tables vary between versions, so check the game's rules before assuming a figure. Low edge doesn't mean low risk of losing in a session. See our video poker apps guide for how the pay table affects the edge.
Is the house edge the same in an app as in a casino?
The maths of a bet is the same anywhere: a single-zero roulette straight-up bet is 2.70% whether you play in an app or at a table. What can differ is the version of a game, such as a different pay table or a double-zero wheel, which changes the edge. UK rules require online operators to show odds information such as the house edge or RTP before you play. Our roulette app guide explains the wheel types.
Can you beat the house edge?
Not with betting systems or patterns. Each bet carries the edge on its own, so changing bet sizes or sequences changes how wins and losses are spread, not the average cost. Wizard of Odds found Martingale players lost at the same rate per pound bet as flat bettors, with extra risk of going broke. In blackjack, basic strategy reduces the edge but doesn't remove it. Read more on blackjack apps.
How do I work out my expected loss?
Multiply the total amount you'll stake by the house edge. Total stake is your bet size times the number of bets, not your starting balance. For example, 200 spins at 50p is £100 staked; at a 4% house edge the expected loss is £4. Actual results will vary, sometimes widely. Our page on budgeting for casino apps shows how to set limits using this figure.
What is the difference between house edge and hold?
House edge is a theoretical figure: the expected loss per bet based on the game's maths. Hold is what a casino actually keeps from the money played over a period, such as a shift, so it depends on how people really played. They're related but measure different things. For you as a player, the house edge is the useful figure, because it tells you the built-in cost of each bet. See payout for how prizes set it.
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