Interactive Tool · House Edge Math
Enter any bet's win probability and payout to calculate the exact house edge, RTP and expected loss.
Enter a win probability and payout above to calculate the house edge on any casino bet.
House edge is calculated from three inputs: the probability of winning, the payout for a win, and the probability of pushing (if applicable).
A negative expected value means the player loses money on average. House edge is expressed as the absolute value — how many cents the casino keeps per dollar wagered. Read the full explanation →
The house edge calculator above lets you evaluate any casino bet by entering its win probability and payout. Behind the simple interface is the same formula that governs every casino game in existence — the expected value equation. Understanding how this formula works makes you a more informed player and lets you evaluate any bet you encounter, even ones not covered in any guide.
Expected value (EV) is the average outcome of a bet if you made it an infinite number of times. For a fair coin flip at even money, the EV is exactly $0 — you'd win as often as you'd lose, with the same payout each time. For any casino bet, the EV is negative — meaning the casino extracts value from you on every repetition. The house edge is simply the EV expressed as a percentage of the amount bet, with the sign removed.
The calculation requires three inputs. First, the probability of winning — a percentage between 0 and 100. Second, the payout — how many dollars you win for every dollar wagered on a win. Third, optionally, the probability of a push — outcomes where your bet is returned without a win or loss.
The preloaded presets cover the most common casino bets. For custom bets — side bets, new games, or obscure wagers — you can enter the probability and payout directly. Finding those inputs requires either looking up the published odds or calculating from the game's structure.
For card game bets, the probability comes from combinatorial analysis — counting how many card combinations produce a win versus a loss, divided by total possible combinations. For dice games, it's counting favorable outcomes versus total outcomes on the dice. For wheel games, it's the number of winning pockets divided by total pockets.
Once you know how to find or calculate these inputs, you can evaluate any casino bet with certainty. This skill eliminates the need to trust any casino's marketing about a game's odds — you can verify them yourself.
The calculator includes an expected loss per hour figure once you enter your bet size and hands per hour. This converts the abstract house edge percentage into a concrete dollar figure that's directly comparable across games.
A 5.26% house edge on a $10 American roulette bet at 40 spins per hour costs an expected $21.04 per hour. The same $10 on a European roulette wheel at the same pace costs $10.80. Blackjack at $10 per hand, 60 hands per hour, basic strategy: $3 per hour. These figures are eye-opening for most players, because the hourly cost of a low-edge game played at modest stakes is genuinely small — comparable to the cost of a movie or a meal, not the ruinous expense that many players fear.
The expected loss figure is also what makes it possible to evaluate whether casino comps represent genuine value. If you are expected to lose $60 in a session and receive a $30 meal comp, the comp represents 50% of your theoretical loss — an excellent return rate. If you extend your session to earn a $30 comp and increase your expected loss to $150, the comp is no longer worth it.
| Bet | Win Prob. | Payout | House Edge |
|---|---|---|---|
| Blackjack — basic strategy | 42.22% | 1:1 (plus 1.5:1 naturals) | ~0.50% |
| Baccarat — Banker | 45.86% | 0.95:1 (after commission) | 1.06% |
| European Roulette — Red | 48.65% | 1:1 | 2.70% |
| American Roulette — Red | 47.37% | 1:1 | 5.26% |
| Baccarat — Tie | 9.51% | 8:1 | 14.36% |
| Craps — Any Seven | 16.67% | 4:1 | 16.67% |
Use the calculator to verify any of these figures or to evaluate bets not listed here. The formula is universal — every casino bet can be reduced to probability and payout.