What Is House Edge?
The house edge is the mathematical advantage the casino has on every bet. It's expressed as a percentage of each wager that the casino expects to keep over the long run. A house edge of 2% means that for every $100 wagered, the casino expects to profit $2 on average.
This doesn't mean you lose 2% every time you play. In the short term, anything can happen — you might win big or lose big. But over thousands of bets, the actual results converge toward the mathematical expectation. This is why casinos are profitable businesses: they don't need to win every hand, they just need the math on their side over millions of transactions.
House Edge by Game
| Game | House Edge | Notes |
|---|---|---|
| Blackjack (basic strategy) | 0.3–0.5% | Lowest edge of any table game with proper play |
| Craps (pass/don't pass) | 1.36–1.41% | Among the best bets in the casino |
| Baccarat (banker) | 1.06% | Banker bet is one of the best in the house |
| Baccarat (player) | 1.24% | Slightly worse than banker |
| Roulette (European, single zero) | 2.70% | One zero gives better odds |
| Roulette (American, double zero) | 5.26% | The extra 00 nearly doubles the edge |
| Video Poker (Jacks or Better, full pay) | 0.46% | With perfect strategy; varies by pay table |
| Slot Machines | 2–15% | Varies wildly; usually not disclosed |
| Keno | 25–30% | One of the worst bets in the casino |
Calculate the expected value of any bet.
Open EV Calculator →How House Edge Is Calculated
The formula is straightforward:
House Edge = (Total Wagered − Total Returned) ÷ Total Wagered
Probability of winning: 18/38 = 47.37%
Probability of losing: 20/38 = 52.63%
On a $1 bet: you win $1 with 47.37% probability, lose $1 with 52.63% probability.
Expected value: ($1 × 0.4737) + (−$1 × 0.5263) = −$0.0526
House edge: 5.26%
For every $100 you bet on red/black, you lose $5.26 on average.
Explore roulette probability for every bet type.
Open Roulette Math Tool →House Edge vs Hold Percentage
Don't confuse house edge with hold percentage. House edge is per bet. Hold percentage is the total amount the casino keeps from your buy-in over a session. Because you typically recycle your winnings into more bets, the hold is much higher than the edge.
Total wagered: $1,000 (you recycled your buy-in through many bets)
Expected loss: $1,000 × 5.26% = $52.60
You started with $100 and expect to leave with about $47 — the casino "held" 53% of your buy-in, despite a house edge of only 5.26%.
Why You Can't Beat the House Edge Long-Term
The Law of Large Numbers guarantees that over enough bets, your results will converge toward the mathematical expectation. In the short term (50–100 bets), variance is high and anything can happen. Over thousands of bets, the house edge grinds down your bankroll.
The only exceptions:
- Blackjack with card counting: Shifts the edge to the player by 0.5–1.5%
- Poker: You play against other players, not the house. The house takes a rake but skill determines who wins.
- Sports betting (sharp bettors): With superior analysis, a small percentage of bettors can maintain a long-term edge
- Video poker (specific pay tables): A few rare machines offer over 100% return with perfect strategy
What This Means for You
Understanding house edge isn't about avoiding casinos — it's about making informed decisions. If you enjoy gambling as entertainment, knowing the math helps you:
- Choose games with lower edges (blackjack over slots)
- Avoid terrible bets (keno, 6:5 blackjack, tie bet in baccarat)
- Set realistic expectations about how much you'll likely lose
- Understand that systems and streaks don't change the underlying math