House Edge Calculator
Casinos and bookmakers profit from the house edge — the mathematically guaranteed gap between odds and true probabilities. This calculator shows at a glance how much you lose on average across a given number of rounds.
House Edge & Expected Value Calculator
Play with the numbers instead of believing them. Pick a game, enter your stake and number of rounds — the calculator shows the mathematically expected loss and how the house edge eats into your bankroll.
Note: Expected value is a long-run average. In the short run you may win or lose much more — that is variance.
What is the house edge?
The house edge is the percentage of your stake the casino keeps long-term. European roulette: 2.7%. American roulette: 5.26%. Sounds small — multiplied across hundreds of rounds it adds up fast.
What is expected value (EV)?
Expected value is the average profit or loss per round if you played infinitely often. With negative EV (every casino game!) you are guaranteed to lose in the long run.
Why play at all?
Gambling is entertainment. If you treat the expected loss as the price of admission — like a cinema ticket — that is fine. It becomes a problem when you reinterpret the loss as an opportunity to win.