The edge is an average advantage per stake
House edge expresses the operator’s theoretical advantage as a percentage of money wagered under particular rules. For a simple game with a 96% RTP, the complementary edge is 4%. That does not mean every player loses 4% of every deposit.
The important denominator is turnover: all the wagers made, including money returned and staked again. Our RTP guide explains the relationship from the player’s return side.
Derive it from a roulette wager
Take a hypothetical standard single-zero roulette wheel with 37 equally likely pockets and a straight-number payout of 35 to 1. A $1 wager wins $35 in profit on one pocket and loses $1 on each of the other 36.
Expected profit = (1 ÷ 37 × $35) − (36 ÷ 37 × $1) = −$1 ÷ 37.
The expected loss per $1 wager is about $0.027, giving a house edge of roughly 2.70%. A win also returns the original stake; that returned stake is not extra profit in this calculation. These assumptions matter: a variant with different payouts needs a different calculation.
Estimate exposure without predicting a session
At a 4% theoretical edge, $200 of accumulated stakes corresponds to an $8 expected loss. One actual session might lose the entire starting balance or end ahead. The expected figure is not an upper limit on loss, and it cannot tell you how much money is needed to complete $200 of wagers.
Doubling turnover doubles that theoretical expected-loss figure if the same assumptions continue to apply. A smaller edge does not automatically mean a smaller session loss if you play for much longer or stake more.
Compare both the rate and the amount wagered
Consider two purely hypothetical sessions, each with a fixed edge applying to all stakes:
| Example | Total stakes | Edge | Theoretical expected loss |
|---|---|---|---|
| A | $100 | 4% | $4 |
| B | $300 | 2% | $6 |
Example B has the smaller percentage but the larger expected loss because turnover is three times higher. Actual outcomes can differ sharply from either figure. The comparison does not rank games or recommend a session length; it shows why a percentage without its stake base cannot describe total exposure.
Check rules before comparing games
A different wheel, blackjack payout or side-bet table changes the calculation. Do not attach one percentage to every game sharing a familiar name. Where player decisions affect return, the calculation also needs a stated strategy assumption.
The official table rules illustrate how bets and payouts are specified; they do not establish the configuration of your online table.
A staking progression changes the amount exposed, not the probabilities of an independent spin. Set money and time limits before play, and avoid treating an expected-loss calculation as a gambling budget recommendation.