Interactive laboratory
House Edge Calculator
Calculate theoretical expected loss from your stake, house edge, rounds per hour and session length. Compare single-zero, double-zero and la partage rules.
How the calculation works
Total stakes = stake per round × rounds per hour × hours. Theoretical expected loss is total stakes multiplied by the house edge. Total stakes counts every wager, including money wagered again after a win.
The roulette presets are derived from their stated rules. With 18 winning and 19 losing pockets, a £1 red/black wager paying 1:1 has a net expectation of (18 − 19) ÷ 37 = −£1/37. Adding a second losing zero gives (18 − 20) ÷ 38 = −£1/19. On single-zero even-money bets with la partage, half the stake is lost on zero, giving −£0.50/37.
Why pace belongs in the comparison
At the same stake and house edge, twice as many paid rounds doubles the modelled total stakes and expected loss. A quick table and a slow table are not equivalent merely because they display the same RTP.
What the answer does not mean
The model is a long-run mean. A session can finish far above or below it. It is not a maximum loss, a recommended budget, a prediction of profit or a measured withdrawal result. It assumes all modelled rounds occur and every stake and rule matches the input. Blackjack decisions, side bets and additional fees require their own correctly scoped inputs.
Worked example
At £5 per round, 60 rounds an hour and one hour, total wagers are £300. A standard single-zero colour bet has a theoretical expected loss of £300 ÷ 37, about £8.11. The corresponding double-zero example is £300 ÷ 19, about £15.79. Single-zero la partage on an eligible even-money bet gives £300 ÷ 74, about £4.05.
At 30 rounds an hour, each amount halves. The example isolates pace: it does not claim that a real table runs at either speed. The roulette probability calculator shows why many different session results can share the same average.
Calculator questions
How do I calculate expected loss from a house edge?
Multiply the total amount wagered by the house edge as a decimal. For example, £300 of wagers at a 2% edge gives £6 of theoretical expected loss. Total wagers include money bet again after wins.
Does a 97% RTP mean I get £97 back from a £100 deposit?
No. RTP relates to long-run returns on wagers under specified rules, not a guarantee on deposits. Repeatedly staking the same balance increases total turnover, and a single session can differ greatly from the average.
Can I use this calculator for blackjack or a game show?
You can enter a known house edge using the custom option, but it must match the exact bet, rules and, where relevant, player decisions. The roulette presets do not describe blackjack, bonus bets or multiplier games.
Why do the bars stay in the same proportions?
All three examples use the same stake, pace and duration. Those inputs multiply every result equally, so the amounts change together while their ratios stay constant. The bars are a comparison chart, not draggable controls.