House edge calculatorComing soon

Preview. This tool is in development. The interface and design are final; the calculation engine is in progress. We will update this page when the engine ships. Until then, check the Methodology page for our assumption stack.

Calculate the house edge for any wager based on payout odds and probability.

MS
Dr Helena Marchant
Quantitative editor · Reviewed 15 May 2026
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How the maths work

The house edge on any single wager is the difference between the fair payout for that bet and the payout the casino offers. Fair means P(win) × fair_payout = P(lose), which gives fair_payout = (1−p)/p. Anything the casino offers below that is the edge, expressed as a fraction of your stake.

Compare-games view plots the edge across the games and rule variants you will actually meet in a London casino. The numbers come from canonical sources: our analysis for blackjack and casino-poker rule sets, the closed-form 1/37 and 2/38 for European and American roulette, 1.06% and 1.24% for baccarat Banker and Player, and UKGC slot RTP disclosures for the slot estimates.

Cost-per-hour view multiplies stake by decisions per hour by edge. That is the most important number on the page. A £25 bet on European roulette costs you about £27 an hour on average. The same £25 on basic-strategy blackjack costs about £8. Tighten the edge, slow the game down, or shrink the stake: those are the three levers.

What this is not

It is not a prediction of any single session. It is a long-run average, and like all averages it hides large swings either side. Use it to budget and compare, not to forecast what tonight will cost.

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