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Casino & Gambling Expected Value Calculator

Every casino game has a built-in mathematical edge that guarantees the house wins over time. Calculate the expected loss for any game — blackjack, roulette, slots, baccarat, craps — based on the real house edge, your bet size, and how long you play.

The house edge is the percentage of every bet the casino keeps on average. It seems small — 1% to 15% — but at hundreds of bets per hour, it adds up fast.

casino Game & House Edge
Percentage the house keeps per bet
Blackjack ~60–80, slots ~400–600
payments Betting Details
Used to calculate ruin probability
trending_up Opportunity Cost
Note: Expected value represents the mathematical long-run average, not any single session outcome. Due to variance, short-term results can differ significantly — which is why gambling feels profitable to many players who are ahead in the short term. The house edge is certain; individual session outcomes are not. If gambling is becoming a problem, call the National Problem Gambling Helpline: 1-800-522-4700.

Casino & Gambling Expected Value

Roulette • $25/bet • 5.26% house edge

Expected Loss Per Hour: $0

Per Hour
-$0
Per Session
-$0
Per Year
-$0
If Invested Instead
$0
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Loss Summary

What You Could Do Instead

Casino Game Comparison — House Edge

GameHouse EdgeBets/hrExpected Loss/hr at $25Rating

"The house doesn’t beat the player because it wins every hand. It beats the player because it stays in the game longer — and the edge does the rest."

— Casino Mathematics

How the house edge works

The house edge is the casino’s mathematical advantage expressed as a percentage of every bet. A 5.26% house edge on American roulette means that for every $100 wagered, the casino expects to keep $5.26 and return $94.74 to players — on average, over millions of bets. No individual spin is predetermined, but the aggregate is as reliable as compound interest.

The edge compounds through the number of bets per hour. A slot machine at $1 per spin and 500 spins per hour with an 8% house edge costs $40/hour in expected losses — more than most table games at $25/hand. The per-spin amount seems trivial; the per-hour amount is not.

Understanding variance is also important. In the short term, luck dominates — which is why you can walk away ahead after any single session. Over thousands of hours, the edge becomes the overwhelming factor. A player who gambles 200 hours per year for 10 years will see results converge very closely to the mathematical expectation regardless of their short-term luck.

lightbulb House Edge Quick Reference

GameHouse EdgeNotes
Video Poker (9/6 JoB)0.46%Near break-even with perfect play
Blackjack (basic strategy)0.5%Must learn and use basic strategy
Craps (pass line)1.41%One of the best table bets
Baccarat (banker)1.06%Simple, low edge
Roulette (American)5.26%Double zero adds extra edge
Slots (average)8%Varies widely; 85–98% RTP
Keno25%+Among the worst bets in the casino
Craps (any 7)16.67%Avoid all prop bets

Gambling Expected Value FAQs

Can you overcome the house edge?

Card counting in blackjack can flip the edge slightly in the player’s favor (+0.5% to +1%) in specific deck compositions. This is extremely difficult, requires continuous practice, and results in casino banning if detected. Video poker with perfect strategy approaches near-zero edge. In general, no strategy eliminates the house edge in casino games — that would make the casino unviable. The closest achievable for most players is minimizing it through game selection and basic strategy.

Why do people feel like they win at slots?

Several psychological mechanisms are at work. Slot machines are designed to deliver near-misses and small wins frequently, which triggers dopamine responses even when the net result is a loss. Wins are celebrated loudly; losses happen silently. Players remember wins vividly and undercount losses. The pace of play (400+ spins/hour) means $40 in losses happens so gradually that each individual loss feels negligible.

What is the best game to play at a casino?

From a pure expected value standpoint: blackjack with basic strategy (0.5%), video poker 9/6 Jacks or Better (0.46%), baccarat banker bet (1.06%), or craps pass line (1.41%). All table games are significantly better than slots. Games with player skill (blackjack) reward study. Avoid roulette with two zeros, any keno, and side bets on any table game — side bets typically have 5–15% house edges.

Terminology

House Edge

The percentage of each bet the casino keeps on average over time. Calculated as (expected casino profit) / (total amount bet). A 5% house edge means the casino expects to profit $5 for every $100 wagered, returning $95 to players as prizes or winnings.

Expected Value (EV)

The probability-weighted average outcome of a bet. In casino games, EV is always negative for the player (by the amount of the house edge). EV = bet size × (win probability × win amount − loss probability × loss amount).

Variance

The statistical spread of outcomes around the expected value. High-variance games (slots, progressive jackpots) produce big swings in either direction. Low-variance games (baccarat, craps pass line) produce steadier, more predictable results. The house edge is the same in the long run; variance only determines the path taken to get there.

Return to Player (RTP)

The inverse of house edge: the percentage of money wagered that is returned to players as wins. A 95% RTP means the house keeps 5%. Slot machine RTPs must be disclosed in most jurisdictions and range from 85% to 98%.

Gambler’s Ruin

A mathematical theorem proving that any player with finite bankroll playing a game with negative expected value will eventually lose all their money if they play long enough. The casino has a functionally infinite bankroll and never needs to stop — the player’s ruin is mathematically certain over a long enough time horizon.

Disclaimer: All calculators on this site are provided for informational and educational purposes only. Results are estimates based on the inputs you provide and mathematical formulas — they do not account for taxes, fees, inflation, risk, or other real-world factors that may affect financial outcomes. Past performance does not guarantee future results. Nothing on this site constitutes financial, investment, legal, or tax advice. Always consult a qualified professional before making financial decisions.

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