🎯 Calculate True vs Casino Odds
Enter the probability of winning or select a common casino bet to see the difference between fair odds and what casinos actually pay.
True Odds Explained: True odds represent the mathematically fair payout based on actual probability. If you have a 50% chance of winning, true odds would pay 1:1. The casino pays 1:1, creating a 0% house edge that costs you $0 per $100 wagered on average.
📊 House Edge Rating
See how this bet compares to typical casino offerings. Lower is better for players.
Verdict: This bet has a fair house edge. You're paying a reasonable price for the entertainment value.
🎰 True Odds Comparison Across Games
See how true odds compare to casino payouts across popular bets. Green shows bets closest to fair odds.
| Game/Bet | Win Probability | True Odds | Casino Pays | House Edge | Cost/$100 |
|---|---|---|---|---|---|
| Craps Odds Bet | Varies | Varies | True Odds | 0.00% | $0.00 |
| Blackjack (Basic Strategy) | ~49.5% | 1.02:1 | 1:1 | ~0.5% | $0.50 |
| Baccarat Banker | 45.86% | 1.18:1 | 0.95:1 | 1.06% | $1.06 |
| Baccarat Player | 44.62% | 1.24:1 | 1:1 | 1.24% | $1.24 |
| Craps Pass Line | 49.29% | 1.03:1 | 1:1 | 1.41% | $1.41 |
| European Roulette (Even) | 48.65% | 1.06:1 | 1:1 | 2.70% | $2.70 |
| European Roulette (Single) | 2.70% | 36:1 | 35:1 | 2.70% | $2.70 |
| American Roulette (Even) | 47.37% | 1.11:1 | 1:1 | 5.26% | $5.26 |
| Craps Any 7 | 16.67% | 5:1 | 4:1 | 16.67% | $16.67 |
| Baccarat Tie | 9.52% | 9.51:1 | 8:1 | 14.36% | $14.36 |
| Keno (Pick 1) | 25% | 3:1 | 2.5:1 | 25%+ | $25.00+ |
Key Insight: The only standard casino bet that pays true odds is the "odds bet" in craps (taken behind pass/come bets). All other bets pay less than true odds, which is how casinos generate profit. According to UNLV Center for Gaming Research, this mathematical advantage ensures casinos remain profitable regardless of short-term variance.
🧮 The True Odds Formula
Understanding how to calculate true odds helps you evaluate any bet's fairness.
For example, with a 25% win probability: True Odds = (1 / 0.25) - 1 = 4 - 1 = 3:1
If true odds are 3:1 and the casino pays 2.5:1: House Edge = ((3 - 2.5) / 4) × 100 = 12.5%
Important: Casino games are designed with house edges ranging from 0.5% (blackjack with perfect strategy) to over 25% (some keno games). Understanding true odds helps you identify which bets offer reasonable value vs. which are mathematical traps. For detailed analysis of game mathematics, see resources from the American Gaming Association.
What Are True Odds in Gambling?
True odds represent the mathematically fair payout for any bet based on its actual probability of winning. If something has exactly a 10% chance of happening, true odds would be 9:1—meaning you'd win $9 for every $1 wagered if you hit the outcome. This is the payout that would result in zero house edge over infinite trials.
Casinos, however, never pay true odds on standard bets (with one notable exception). Instead, they pay slightly less, and this difference is their profit margin—the house edge. Understanding this fundamental concept is essential for any informed gambler, as described in Britannica's comprehensive gambling overview.
How Casinos Create Their Edge
Every casino game is designed to pay less than true odds. Consider European roulette:
- Single number probability: 1/37 = 2.703% (37 pockets including zero)
- True odds payout: 36:1 (you'd win 36× your bet for hitting 1 in 37)
- Casino payout: 35:1 (one unit less than true odds)
- House edge: 1/37 = 2.70% (that missing unit)
This seemingly small difference compounds dramatically over time. Our House Edge Calculator shows exactly how much this costs over extended play.
The Only Bet That Pays True Odds
In standard casino games, the craps "odds bet" is unique—it's the only bet that pays true mathematical odds with zero house edge. The catch? You can only make this bet after placing a pass/don't pass or come/don't come bet, which does have a house edge.
The odds bet pays:
- Points 6 or 8: 6:5 (true odds for rolling 6 or 8 before 7)
- Points 5 or 9: 3:2 (true odds for rolling 5 or 9 before 7)
- Points 4 or 10: 2:1 (true odds for rolling 4 or 10 before 7)
Smart craps players maximize their odds bets (casinos limit these) to dilute the house edge on their pass line bets. Learn more in our comprehensive craps guide and Craps Bet Analyzer.
Sports Betting and True Odds
Sports betting operates differently but the concept remains the same. For a true 50/50 event (coin flip), fair odds would be +100 on both sides (2.00 decimal). Instead, sportsbooks typically offer -110 on both sides, taking a 4.55% margin.
The UK Gambling Commission requires operators to be transparent about odds, but understanding true odds helps you identify value. Use our Vig Calculator to see exactly how much sportsbooks take on any market.
Why True Odds Matter for Bankroll Management
Understanding the gap between true odds and casino payouts is crucial for realistic expectations:
- Session planning: Know how much you'll mathematically lose on average per hour
- Game selection: Choose games with smaller gaps (lower house edges)
- Bet sizing: Understand the cost-per-bet to size appropriately
- Long-term outlook: Accept that the house edge cannot be overcome through betting systems
Our Bankroll Management Guide and Session Planner help you apply this knowledge practically.
Common True Odds Misconceptions
Several myths persist about true odds and casino mathematics:
- "Some bets are due": False. Each bet is independent; true odds don't change based on history
- "Systems can create true odds": False. No betting system changes the underlying mathematics
- "Higher payouts mean better odds": False. Long-shot bets often have the worst true odds gap
- "Casinos cheat on odds": False. Licensed casinos pay advertised odds; the edge is built into game design
For more on gambling myths, see our Common Casino Myths Explained article.
Frequently Asked Questions
What are true odds in gambling?
True odds represent the actual mathematical probability of an event occurring, expressed as a payout ratio. If something has a 1 in 37 chance (like hitting a single number in European roulette), true odds would pay 36:1. Casinos pay less than true odds (35:1 for roulette) to maintain their house edge.
How do you calculate true odds?
True odds are calculated as (total outcomes / winning outcomes) - 1. For a single roulette number: (37/1) - 1 = 36:1 true odds. For a coin flip: (2/1) - 1 = 1:1 (even money). The formula converts win probability into the fair payout that would result in zero house edge.
Why don't casinos pay true odds?
Casinos are businesses that need profit to operate. By paying slightly less than true odds on every bet, they guarantee long-term profit regardless of short-term variance. This difference between true odds and actual payouts creates the house edge—typically 1-15% depending on the game and bet type.
What bets pay true odds?
The only common casino bet that pays true odds is the "odds bet" in craps, taken behind pass/don't pass or come/don't come bets. This bet has zero house edge. However, you must first make a pass/come bet (which has house edge) to access the odds bet. No other standard casino bet pays true odds.
How much does the house edge cost per bet?
The house edge cost per bet equals your wager times the house edge percentage. On a $100 bet with 5% house edge, you're statistically losing $5 per bet in the long run. Over many bets, this cost compounds—100 bets at $100 each with 5% edge costs you $500 on average.
Are sports betting odds true odds?
No, sportsbook odds include the bookmaker's margin (vig/juice). For a 50/50 event at true odds, both sides would be +100 (2.00 decimal). Instead, books typically offer -110 on both sides, meaning they pay less than true odds. The difference is usually 4-10% depending on the book and market.
How do I find the best value using true odds?
Compare the implied probability from offered odds to your estimate of true probability. If a bet offers +200 (implied 33.3% probability) but you believe the true probability is 40%, you've found value—you're getting paid at worse-than-true odds but for something more likely than the odds suggest.
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