Roulette is a game of chance, but the cost of playing doesn’t have to be a mystery. Every bet on the table has a built-in mathematical advantage for the casino, known as the House Edge. Whether you play for fun or are a high roller chasing comps, knowing your “Theo” (Theoretical Loss) is the most important part of bankroll management.
Use our free Roulette House Edge Calculator below to determine exactly how much a session will cost you on average. This tool functions as a precise casino expected loss calculator, factoring in wheel type, game speed, and specific betting rules.
How to Use the Calculator
This tool allows you to simulate a gambling session expected loss calculator. By inputting your betting habits, you can see the long-term cost of your strategy.
- Select Wheel Type:
- European: The standard single-zero wheel (Best odds).
- American: The double-zero wheel found in Vegas (Higher risk).
- Triple Zero: Found in some modern casinos (Avoid if possible).
- Select Bet Category: Most bets have the same edge, but there are exceptions like the “Basket Bet” (0-00-1-2-3) or Even Money bets with special rules.
- Input Session Details: Enter your average Bet Amount, the Game Speed (spins per hour), and how many Hours you plan to play.
The roulette expected value calculator will instantly show you the House Edge percentage and the total expected loss in dollars.
Real-World Examples: The Cost of Playing
Why does wheel selection matter? Let’s look at the math using our roulette expected loss calculator. Assume two players both bet $20 per spin for 2 hours (120 spins total).
Example 1: The “Vegas Strip” Player (American Wheel)
- Wheel: American (Double Zero).
- Total Wagered: $2,400.
- House Edge: 5.26%.
- Expected Loss: -$126.24.
Example 2: The “Smart” Player (European Wheel)
- Wheel: European (Single Zero).
- Total Wagered: $2,400.
- House Edge: 2.70%.
- Expected Loss: -$64.80.
Result: By simply finding a Single Zero wheel, the second player cuts their expected loss in half.
Example 3: The “Basket Bet” Trap
If you bet on the “Five Number Bet” (0, 00, 1, 2, 3) on an American wheel, the house edge calculator roulette logic changes. The edge spikes to 7.89%. Over the same 2-hour session, your expected loss jumps to -$189.36.
Understanding Theoretical Loss (Theo)
Casinos use this exact math to determine your “Value” as a player. They don’t care if you won or lost today; they care about your Theoretical Loss.
Theo = Total Wagers × House Edge
This is why our tool includes an “Est. Comp Value” field. Casinos typically return 10% to 20% of your theoretical loss in the form of free drinks, meals, or rooms. If you know your Theo, you know exactly how many comps you deserve.
Frequently Asked Questions (FAQ)
What is the House Edge in Roulette?
On a standard European wheel (Single Zero), the house edge is 2.70%. On an American wheel (Double Zero), the edge is 5.26%. This means for every $100 you bet, the casino expects to keep $2.70 or $5.26 in the long run.
What is the “La Partage” rule?
La Partage is a special rule found in some French/European roulette games. If you make an Even Money bet (like Red/Black) and the ball lands on Zero, you get half your bet back. This cuts the house edge in half, down to 1.35%.
How do I calculate expected loss per hour?
The formula is: Avg Bet × Spins Per Hour × House Edge. For example, betting $10/spin at 50 spins/hour on a European table: $10 × 50 × 0.027 = $13.50 per hour.
Can I overcome the House Edge?
No betting system (like Martingale or Fibonacci) can mathematically overcome the house edge in the long run. The roulette expected value calculator will always show a negative EV because the payouts (35 to 1) are lower than the true odds of winning (1 in 37 or 38).