Roulette EV Calculator

Calculate the expected value of any roulette bet. Compare American vs European wheels, factor in La Partage rules, and understand your mathematical expectation over any number of spins.

Formula:EV = (Win Probability × Win Amount) - (Lose Probability × Bet Amount)

Expected Value (EV)

-$0

House Edge

2.70%

Win Probability

48.65%

Bet Setup

$

Amount wagered per spin

Calculate EV over multiple spins

EV Calculation Breakdown

Win Probability48.6486%
Lose Probability51.3514%
Payout1:1
Win Amount$10
Loss Amount$10
Expected Win Value$5
Expected Loss Value-$5
Net EV Per Bet-$0

EV Comparison by Wheel Type

Bet TypeEuropean EVAmerican EVDifference
Straight Up-$0-$1$0 better
Split-$0-$1$0 better
Street-$0-$1$0 better
Corner-$0-$1$0 better
Six Line-$0-$1$0 better
Column-$0-$1$0 better
Dozen-$0-$1$0 better
Red-$0-$1$0 better

* All comparisons based on $10 bet. European wheel always has better EV due to single zero.

Quick Answer

A $10 bet on Red at a European wheel has an EV of -$0.27 (2.70% house edge). On an American wheel with double zero, the same bet has EV of -$0.53 (5.26% house edge).

Key Facts

  • EV = (Win Probability x Payout) - (Lose Probability x Bet Amount)
  • European wheel: Every $100 wagered loses $2.7 on average
  • American wheel: Every $100 wagered loses $5.26 on average
  • Negative EV is unavoidable - no bet or system can overcome it long-term
  • La Partage/En Prison rules on even money bets cut house edge to 1.35%
  • Over 1,000 spins, actual results converge toward expected value

Understanding Expected Value in Roulette

Expected Value (EV) is the mathematical average outcome of a bet over infinite repetitions. In roulette, EV is always negative because payouts are based on 36 numbers while the wheel has 37 (European) or 38 (American) numbers. The zero(s) give the house its edge.

The EV Formula

EV = (Probability of Winning × Payout) - (Probability of Losing × Bet Amount)

For a $10 bet on Red at European roulette:

  • Win Probability: 18/37 = 48.65%
  • Lose Probability: 19/37 = 51.35%
  • EV = (0.4865 × $10) - (0.5135 × $10) = -$0

Frequently Asked Questions

What is Expected Value (EV) in roulette?

Expected Value is the average amount you can expect to win or lose per bet over the long run. For a $10 bet on Red at European roulette, EV = (18/37 x $10) - (19/37 x $10) = -$0.27. This means you lose $0.27 on average per $10 bet.

Why is roulette EV always negative?

Roulette EV is negative because of the zero (and double zero on American wheels). While payouts are calculated as if there were 36 numbers, there are actually 37 or 38. This gap creates the house edge - the casino's mathematical advantage on every bet.

Which roulette bets have the best EV?

On European roulette, all standard bets have the same -2.70% EV (except La Partage/En Prison even money bets at -1.35%). On American roulette, avoid the 5-number basket bet which has -7.89% EV. The best EV is European with La Partage at -1.35%.

Can betting systems overcome negative EV?

No betting system can overcome negative EV long-term. While systems like Martingale can win short-term, the math is inescapable: over enough spins, total losses approach the expected value. A $1,000 total wagered will average $27 loss on European and $52.60 loss on American roulette.

How do I calculate expected loss for a session?

Expected Loss = Total Wagered x House Edge. If you bet $25 per spin for 100 spins ($2,500 total) on European roulette, expected loss = $2,500 x 2.70% = $67.50. Actual results will vary, but this is the statistical average.