Roulette Payout Calculator (payout odds, house edge & expected loss per bet)

Understanding the roulette payout calculator — concept and principle

This calculator shows what each roulette bet pays, the chance of winning, the house edge and the expected result per spin and over many spins, for single-zero (European) and double-zero (American) wheels. Use it to understand the odds before playing, to compare bets, or for probability lessons.

The green zero is the extra pocket that gives the house its 1/37 edge.

How it is calculated

Pockets N: 37 (single zero) or 38 (double zero). A bet covers n numbers.
Chance of winning = n ÷ N.
Payout "k to 1": straight 35, split 17, street 11, corner 8, top line 6, six line 5, dozen or column 2, even money 1. The stake comes back on top.
Expected result per unit staked = (n/N)·k − (1 − n/N).
Expected result over all spins = per-spin result × number of spins.
Fair payout odds (no house edge) = (N − n) ÷ n.

With the half-back option, even-money bets lose only half the stake when a zero wins.

The principle

The payouts are set as if the wheel had only 36 numbers. A straight bet pays 35 to 1, which would be fair with 36 pockets, but the zero (and 00) add pockets that the bank collects on. That gap is the house edge: 1/37 ≈ 2.70% on a single-zero wheel and 2/38 ≈ 5.26% on a double-zero wheel, the same for almost every bet. The top-line bet on a double-zero wheel is worse, about 7.89%. Each spin is independent, so no sequence of bets or betting system changes the expected result.

Worked example

Default inputs: single zero, even-money bet, stake $10, 100 spins, no half-back.

Chance of winning: 18 ÷ 37 ≈ 48.65%.
Payout 1 to 1: profit $10, total paid back $20.
Expected result per spin: 10 × (18/37 × 1 − 19/37) = −10/37 ≈ −$0.27.
Over 100 spins: −$0.27027 × 100 ≈ −$27.03; expected wins 48.6.
House edge 1/37 ≈ 2.7%; fair odds would be 19 ÷ 18 ≈ 1.056 to 1.

How to read the result

The expected result is the long-run average loss; in a short session you may win or lose much more. The chance of at least one win shows how likely a bet is to hit at all over the spins, not whether you will finish ahead. Comparing wheels shows the single-zero wheel roughly halves the house edge.

Common mistakes

Believing red is "due" after several blacks; spins are independent.
Thinking progressive systems such as doubling after a loss beat the edge; they only change the shape of the risk.
Forgetting that "35 to 1" means a win returns 36 units including the stake.
Ignoring local rule differences such as half-back rules on even-money bets.

Keep in mind: This is a mathematical illustration, not betting advice. Every roulette bet has a negative expected value, and gambling can cause financial harm. Check the rules where you play, as payouts and zero rules can differ.

Frequently asked questions

Which roulette bet has the lowest house edge?

On a standard wheel nearly all bets share the same edge; even-money bets are lower only where a half-back rule applies.

What is the house edge on an American wheel?

About 5.26% for most bets, and about 7.89% for the five-number top line.

Can a betting system make roulette profitable?

No. Every bet has the same negative expectation, so any combination of bets does too.

Sources: New Jersey Administrative Code § 13:69F-5.2, "Roulette: payout odds"

Checked 9 Nov 2026. New Jersey Administrative Code § 13:69F-5.2 “Roulette: payout odds” (straight 35 to 1, split 17 to 1, three numbers 11 to 1, four numbers 8 to 1, first five numbers 6 to 1, six numbers 5 to 1, column and dozen 2 to 1, red/black/odd/even/1–18/19–36 1 to 1; on a double-zero wheel the casino may take only half of even-money bets when 0 or 00 wins). Expected values computed from these odds.

Your numbers