Home › Numbers › 21

Number 21 — the complete card

21 pays 35:1 straight-up ($10 wins $350 profit) on every wheel. It’s red, odd, high (19–36), dozen 2, column 3, and hits 1 in 37 European spins / 1 in 38 American. ⚙ computed

On the wheel

European rim, reading 19 · 4 → 21 → 2 · 25. American rim: 18 · 6 → 21 → 33 · 16. Racetrack membership: Voisins du Zéro — the announced bets that physically cover this pocket (math here). “Neighbour” talk means the rim, never the felt — two different maps.

On the felt

Street trio: 19-20-21 (11:1). Split partners on the grid: 20, 18, 24 (17:1 each) — an edge-of-grid number, fewer corners than the interior. Every combination prices identically: the 36-pocket fiction doesn’t care which squares you pick.

Betting 21 — the honest numbers

At $10 per spin, 100 spins of straight 21 wagers cost an expected $27 on European wheels and $53 on American — identical to any bet, wrapped in maximum volatility (SD 5.8). Back-to-back 21: 1 in 1,369. In our 3.7-million-spin reference run, 21 landed 99,783 times against 100,000 expected (-0.22%) — textbook uniformity, the same verdict every number gets.

Put a chip on 21 in the simulator →

Related

← 2022 →all numbersstraight-up math“best numbers” vs data

Frequently asked

What does 21 pay in roulette?
35 to 1 straight-up — a $10 bet returns $350 profit plus your stake. Splits touching 21 pay 17:1, its street 11:1.
Is 21 red or black in roulette?
21 is red — fixed by the traditional color chart on every wheel, odd and high (19–36) for outside-bet purposes.
What are the neighbours of 21 on the wheel?
European rim: 4 and 2 adjacent, 19 and 25 beyond — a five-number “neighbours” call covers exactly this arc. Felt neighbours are different animals — wheel order and grid order share nothing.