🎲 House edge
What a session costs on average, and the variant comparison: European 2.70% vs American 5.26%.
📊 House Edge Calculator
Calculate mathematical expectation (EV-) and expected session loss.
- European Roulette (1 Zero): 2.70% vs American Roulette (2 Zeros): 5.26%
- Blackjack (3:2 Payout): ~0.50% vs Blackjack (6:5 Payout): ~1.89%
⚠️ The house edge guarantees long-term casino profit. Betting strategies do not alter this mathematical disadvantage. Play responsibly. 18+.
What it is
The house edge is the mathematical advantage built into every casino game. It represents the percentage of each wager the operator expects to keep over the long run. For example, a 2.7% edge on roulette means the house expects to hold $2.70 of every $100 bet, averaged across millions of spins. This calculator lets you estimate the expected cost of any game based on its rules, your bet size, and time played.
How it works
The house edge comes from the game's rules. In European roulette (37 numbers), a bet on red covers 18 numbers, leaving 19 losing outcomes. The probability of winning is 18/37, so the house edge is (37 − 2×18) / 37 = 1/37 ≈ 2.7027%. For American roulette (38 numbers, two zeros), it's 2/38 = 5.2632%. French roulette with La Partage returns half the bet on even-money bets when the ball lands on zero, cutting the edge to 1/74 ≈ 1.3514%.
Expected loss per hour = Average Bet × Rounds per Hour × House Edge. For a $10 average bet, 60 rounds per hour, and European roulette (2.7027%): $10 × 60 × 0.027027 = $16.22 per hour. Over a 3‑hour session: $16.22 × 3 = $48.66. Total volume wagered = $10 × 60 × 3 = $1,800. The table shows the same calculation for American roulette: $10 × 60 × 0.052632 = $31.58 per hour, $94.74 per session, and for French La Partage: $10 × 60 × 0.013514 = $8.11 per hour, $24.33 per session.
How to use it
- Select the game category from the dropdown — European Roulette, American Roulette, or Blackjack variants — to auto‑fill the house edge, or use 'Custom' to enter your own RTP in the next field.
- Enter the declared RTP percentage if you chose 'Custom' or want to override the rule‑based edge; the calculator will derive the house edge as 100% minus RTP.
- Input your average bet amount in dollars, the number of rounds you play per hour, and the total hours you expect to play.
- Read the House Edge percentage, Expected Loss per hour, Expected Loss per session, and Total Volume Wagered in the results panel.
- Compare edges across variants in the table below the calculator — the session cost for each game is computed automatically using your inputs.
How to read the result
- House Edge is the long‑term theoretical hold. It does not predict what will happen in your next session; in the short term, variance dominates.
- Expected Loss per hour and per session are averages over many identical sessions. Your actual result will almost surely differ, possibly by a lot.
- Total Volume Wagered is the sum of all bets placed. Even if you win, you might owe taxes on this amount (depending on your jurisdiction), so keep it in mind.
When not to trust the result
- The expected loss is a mathematical average over millions of rounds. In a few hours, standard deviation can easily be several times the expected loss — you might win or lose far more than the calculator shows.
- The house edge is fixed by the rules and cannot be reduced by any betting system, streak tracking, or 'strategy' that doesn't change the game's probability structure.
- Declared RTP on slot machines is often an average over all possible configurations and may not reflect the specific settings chosen by the operator. Always check the machine's paytable.
- Blackjack is not listed as a fixed variant because its house edge depends on exact table rules (payout for blackjack, number of decks, dealer stands on soft 17, doubling options) and on the player's use of basic strategy. Realistic edges come from simulation, not a simple formula. Use the 'Custom' RTP option if you have a reliable edge estimate for your specific game.
- This calculator assumes you are playing consistently and without interruptions. Taking breaks, changing bet sizes, or playing multiple hands at once changes the math.
Frequently asked questions
- Is the house edge the same as the RTP?
- They are complements. RTP (Return to Player) is the percentage of wagered money the game returns on average; House Edge = 100% − RTP. For example, European roulette has an RTP of 97.30% and a house edge of 2.70%.
- Why isn't blackjack in the variant list?
- Blackjack's edge depends on many rule details and on player skill. Even 'perfect' basic strategy yields different edges for different rule sets. Rather than provide a single number that may be wrong for your table, we let you enter a custom RTP if you have a reliable edge estimate.
- Can I lose more than the expected loss?
- Yes, and you can win more too. The expected loss is an average over many sessions. In a single session, variance is high — you could be down two or three times the expected loss after a few hours. That's normal.
- Does the calculator work for slot machines?
- It does, but only as a rough guide. Slot RTPs are often averages over millions of spins and can vary by machine or operator setting. Use the 'Custom' option with the RTP listed on the machine, and remember that actual short‑term results will diverge significantly.