Gambling Odds Calculator
See why the house always wins
Pick a casino game, set your bankroll and number of rounds, and see how much the math guarantees you'll lose over time. Toggle between an expert who plays perfectly and a typical player to see how little strategy changes the outcome.
Select a game
Player type
Goes with gut feeling, often deviates from basic strategy
Blackjack
6-deck, dealer stands on soft 17
2.00%
$2,000
-$40
$960
Expected Bankroll Over Time
95% confidence band shownAfter 200 rounds of Blackjack, you can expect to keep $960 of your $1,000 bankroll.
That's a 4.0% loss, and the math only gets worse the longer you play.
Why You Mathematically Cannot Beat the Casino
The House Edge Is Built In
Every casino game is designed so the expected payout is less than the amount wagered. Roulette has 37 or 38 slots but pays as if there were 36. Blackjack rules favour the dealer. This mathematical advantage is baked into the rules. It cannot be removed by any betting system or strategy.
The Law of Large Numbers
In the short term, luck can go either way. But the Law of Large Numbers guarantees that over hundreds or thousands of bets, your actual results will converge toward the expected value, which is always negative for the player. The more you play, the more certain the loss becomes.
No System Can Overcome Negative EV
Martingale, Fibonacci, D'Alembert: no betting system changes the expected value of a game. Doubling your bet after a loss doesn't create an edge; it just increases variance. You'll either hit a table limit or run out of money before recovering. The math is unbeatable.
The Gambler's Ruin
A player with a finite bankroll playing against a casino with a virtually unlimited bankroll will eventually go broke, even if the game were perfectly fair. With a negative expected value, this outcome is not just likely, it's mathematically inevitable given enough time.
The only guaranteed way to not lose money gambling is to not gamble. If you or someone you know struggles with gambling, contact the National Council on Problem Gambling (1-800-522-4700).
Disclaimer: House edges shown are based on standard game rules and published casino mathematics. Actual results vary by casino, specific rules, and number of decks. This calculator is for educational purposes only and is not gambling advice.