Methodology
How we calculate house edge
The math, the ranges, and the sources behind the house-edge calculator at /tools/house-edge. Last updated 2026-05-04.
House edge is the percentage of every wager a casino keeps over the long run. It is fixed by the game’s rules and your strategy — not by luck on any single session. Blackjack with basic strategy carries a house edge as low as 0.4%; American roulette’s five-number bet runs as high as 7.89%. This page documents how we compute the per-game ranges shown in our calculator and where the data comes from.
Why this exists
The expected loss on any casino game is determined by the house edge — the percentage of every wager the operator keeps on average over enough plays. The number isn’t a single value. It depends on the rules of the specific table or machine, the player’s strategy, and (for slots) the operator’s chosen RTP setting. We show ranges, not single numbers, because anything else would be misleading.
The math
Expected loss = total wagered × (house edge / 100)
Total wagered = bet size × number of bets
Expected return = total wagered − expected lossThe calculator computes both bounds simultaneously: best-case (lowest house edge for the game family) and worst-case (highest). Result is shown as a range — “Expected loss: $4 – $20” — to make explicit that the actual outcome depends on inputs we can’t see (your strategy, the table’s rule variant, the slot’s RTP setting).
Range bounds — what drives best vs worst
- Best-case (low edge): the most player-favorable rule set published anywhere, with optimal player strategy. For blackjack: 8-deck, S17, DAS, late surrender, basic strategy → 0.4%.
- Worst-case (high edge): common worst rules combined with naive play. For blackjack: average non-strategy play on common tables → 2.0%.
- Single-value games: some games are mathematically uniform — European roulette is 2.7% on every bet. For those, low and high are equal.
- Trap bets: we surface the worst single-bet edge per game (e.g. baccarat tie at 14.36%, craps any-7 at 16.67%) as the high bound to make the trap explicit.
Per-game data
| Game family | Best | Worst | Source |
|---|---|---|---|
| Blackjack | 0.4% | 2.0% | Wizard of Odds rule-variant tables |
| European Roulette | 2.7% | 2.7% | Wizard of Odds (uniform) |
| American Roulette | 5.26% | 7.89% | Wizard of Odds (five-number bet is the trap) |
| Baccarat | 1.06% | 14.36% | Wizard of Odds (banker → tie) |
| Craps | 0.6% | 16.67% | Wizard of Odds (don’t pass + odds → any 7) |
| Slots | 2.0% | 12.0% | UKGC RTP dataset; operator pages |
| Video Poker | 0.46% | 5.0% | Wizard of Odds (9/6 → 6/5 Jacks) |
| Pai Gow Poker | 1.46% | 2.84% | Wizard of Odds |
| Crash games | 1.0% | 5.0% | Operator-published RTPs (Stake-class) → less-reputable variants |
| Keno | 20.0% | 35.0% | Wizard of Odds; state lottery data |
Per-platform RTP tracking was considered and decided against — most operators don’t publish RTP data, and the few that do (Cloudbet, Stake at times) are tracked opportunistically rather than systematically.
Limitations
- We don’t model jackpot variance. Progressive slots can have positive expected value during “+EV jackpot” windows; the calculator’s ranges don’t capture this.
- Player skill is binarized. The bounds assume either optimal strategy or no strategy. Real play is in between.
- RTP setting per slot is operator-controlled and rarely published. We use industry averages.
- Comp points and rakeback are not in the calculator; they offset house edge but vary too widely to embed here.
Run the math yourself
The calculator at /tools/house-edge uses this exact data. Pick a game family, enter your bet size and play volume, see the expected loss range. Click “Show what drives this range” on any result for the rule-variant breakdown.