What is the house edge in roulette?

On a European (single-zero) wheel the house edge is 2.70% for all standard bets. On an American (double-zero) wheel it rises to 5.26% because there are 38 pockets instead of 37. The five-number bet on an American wheel is even worse at 7.89%.

What does expected value mean here?

Expected value (EV) is the average gain or loss per dollar wagered in the long run. An EV of -$0.053 means you lose about 5.3 cents on average for every dollar you bet, regardless of short-term luck.

Which roulette bet has the best odds?

Even-money bets (red/black, odd/even, high/low) have the highest win probability — roughly 47.4% on American and 48.6% on European — but all bets carry the same house edge on a given wheel, except the American five-number bet which is worse.

How is the payout ratio calculated?

Casinos pay straight-up bets 35:1, which would be fair on a 36-pocket wheel. Because wheels have 37 or 38 pockets the casino keeps the difference, creating the house edge. The calculator uses the standard Las Vegas payout schedule.

Does this apply to online roulette?

Yes. Reputable online casinos use the same payout schedules. Always verify the wheel type (single-zero vs double-zero) in the game rules; a single-zero wheel gives you meaningfully better odds.

Roulette Odds Calculator

Pick a wheel type and bet, then see exact win probability, payout ratio, house edge, and expected value per dollar wagered.

Roulette Bet Settings

Wheel Type

Bet Type

Wager Amount ($)

Win Probability

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— in — chance

Payout Ratio

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Win $— on $— bet

House Edge

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Casino's long-run advantage

Expected Value

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Average per bet

Detailed Breakdown

Select a bet type and click Calculate.

Win vs. Lose Probability

Win: — Lose: —

Expected Loss Over Multiple Spins

Spins	Total Wagered	Expected Loss
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Summary

This calculator computes exact win probability, payout ratio, house edge, and expected value for every standard roulette bet on both American (38-pocket, 00) and European (37-pocket, 0) wheels. Results update instantly when you change the wheel type, bet selection, or wager amount — no guesswork, just the math casinos use.

How it works

Select American (00) or European (0) wheel.
Choose a bet type from the dropdown (straight, red/black, dozen, etc.).
Enter the amount you plan to wager.
Read the win probability, payout, house edge, and expected value instantly.
Switch bet types or wheel to compare outcomes side by side.

Use cases

Understand the true odds before placing a roulette bet.
Compare house edge between American and European tables.
Calculate expected loss over a session for any bet size.
Teach probability and expected value concepts using a real casino game.
Evaluate which bet type gives the lowest house advantage.
Plan a bankroll knowing exact long-run return per dollar.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu