Roulette Outside Bet Calculator: Lower Risk, Steady Action

Outside bets cover large sections of the wheel—red/black, odd/even, high/low—paying even money or 2:1. Our calculator shows win probabilities, expected value, and why outside betting offers the most consistent roulette experience.

What Are Outside Bets?

Outside bets are wagers placed in the outer sections of the roulette layout, covering 12-18 numbers at once. They include even-money bets (red/black, odd/even, high/low) and 2:1 bets (dozens, columns). Lower payouts but higher win frequency.

Quick Answer: Even-money bets (red/black, odd/even, 1-18/19-36) win 48.65% (European) paying 1:1. Dozens/columns win 32.43% paying 2:1. Same house edge as inside bets (2.70% European). Outside bets offer consistency—you'll win roughly half the time. Better for casual play and extending sessions. Same long-term cost as any roulette bet.

How to Use Our Calculator

Use the Outside Bet Calculator →

Enter bet type and amount to see probabilities and expected value.

Step-by-Step Instructions

1. Select Bet Type: Even money or 2:1

2. Enter Bet Amount: Your wager

3. Choose Roulette Type: European or American

4. View Win Probability: Coverage percentage

5. Calculate Expected Value: Average return

Input Fields Explained

Field	Description	Example
Bet Type	Outside bet selection	Red
Bet Amount	Wager	$25
Roulette Type	European/American	European
Coverage	Numbers covered	18
Win Probability	Percentage	48.65%
Payout	On win	1:1
House Edge	Casino advantage	2.70%

Even-Money Bets

Red or Black

Red numbers: 1,3,5,7,9,12,14,16,18,19,21,23,25,27,30,32,34,36
Black numbers: 2,4,6,8,10,11,13,15,17,20,22,24,26,28,29,31,33,35
Coverage: 18 numbers each

European:
Win probability: 18/37 = 48.65%
House edge: 2.70%

American:
Win probability: 18/38 = 47.37%
House edge: 5.26%

Odd or Even

Odd: 1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35
Even: 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36
Coverage: 18 numbers each

Same probabilities as red/black
Same house edge
Different numbers, identical math

High or Low (1-18 / 19-36)

Low (Manque): 1-18
High (Passe): 19-36
Coverage: 18 numbers each

Same probabilities as other even-money
Some players prefer number ranges
Sequential vs scattered coverage

2:1 Outside Bets

Dozens

First dozen: 1-12
Second dozen: 13-24
Third dozen: 25-36

Coverage: 12 numbers each
Payout: 2:1

European:
Win probability: 12/37 = 32.43%
House edge: 2.70%

Columns

First column: 1,4,7,10,13,16,19,22,25,28,31,34
Second column: 2,5,8,11,14,17,20,23,26,29,32,35
Third column: 3,6,9,12,15,18,21,24,27,30,33,36

Coverage: 12 numbers each
Payout: 2:1

Identical math to dozens
Different number patterns

Expected Value Calculations

Even-Money Bet (European)

$20 bet on red:

Win: $20 × 48.65% = $9.73
Lose: -$20 × 51.35% = -$10.27

EV = $9.73 - $10.27 = -$0.54
House edge: 2.70%

2:1 Bet (European)

$20 bet on first dozen:

Win: $40 × 32.43% = $12.97
Lose: -$20 × 67.57% = -$13.51

EV = $12.97 - $13.51 = -$0.54
House edge: 2.70%

Same expected loss as even-money!

American vs European Comparison

$20 even-money bet:

European (2.70% edge):
Expected loss: $0.54

American (5.26% edge):
Expected loss: $1.05

Nearly double the cost!

Real-World Examples

Example 1: Session Planning

Goal: 2-hour session, $200 budget

Strategy: $10 red/black bets

Estimated spins: 60/hour × 2 = 120 spins
Total wagered: $1,200

European expected loss:
$1,200 × 2.70% = $32.40

With variance, could lose/win more
But average session costs ~$32
Budget of $200 should last

Example 2: Combining Outside Bets

Strategy: $10 red + $10 first column

Analysis:

First column: 5 red, 7 black numbers
Red covers: 18 numbers
Combined coverage: 18 + 7 = 25 unique numbers

Outcomes:
Both win (5 numbers): +$30
Only red wins (13 numbers): +$0
Only column wins (7 numbers): +$10
Both lose (12 numbers): -$20

Each bet has its own 2.70% edge
Combined doesn't change math

Example 3: Martingale on Red

Starting bet: $5 on red

Sequence:

Lose: Bet $10
Lose: Bet $20
Lose: Bet $40
Lose: Bet $80
Lose: Bet $160
Win: Profit $5

Risk: 6 losses = -$315
Reward: +$5

Probability of 6 red losses: ~1.8%
Happens more than you'd think
Eventually wipes out bankroll

Example 4: Flat Betting Reality

Strategy: $25 on black, 100 spins

Expected results:

Wins: ~49 times
Losses: ~51 times

Expected outcome:
49 × $25 - 51 × $25 = -$50
(2% of $2,500 wagered)

Actual 2.70% edge = -$67.50
Variance causes deviation

Outside vs Inside Bets

Comparison Table

Bet Type	Coverage	Payout	House Edge
Red/Black	18	1:1	2.70%
Odd/Even	18	1:1	2.70%
High/Low	18	1:1	2.70%
Dozens	12	2:1	2.70%
Columns	12	2:1	2.70%
Single Number	1	35:1	2.70%
Split	2	17:1	2.70%
Street	3	11:1	2.70%

Key insight: Same house edge for all bets!

Why Choose Outside?

Advantages:
- Win roughly half the time
- Lower variance
- Longer sessions
- Less emotional swings

Disadvantages:
- Lower payouts
- No big wins
- Same long-term cost

La Partage and En Prison

La Partage Rule

When zero hits on even-money bet:
Get half your bet back
Other half to house

Effect:
House edge: 1.35% (half of 2.70%)
Only applies to even-money bets

Where found:
French roulette
Some European tables
Online casinos

En Prison Rule

When zero hits on even-money bet:
Bet stays "in prison"
Next spin determines fate

If your bet wins: Get bet back (no profit)
If your bet loses: Lose bet

Effect:
House edge: ~1.35%
Same as La Partage mathematically

Common Mistakes

1. Assuming Patterns Exist

Mistake: "Red hit 5 times, black is due" Problem: Each spin is independent Fix: Understand randomness

2. Thinking Outside Is Safer

Mistake: "Even-money means I can't lose much" Problem: Same house edge, lower variance doesn't mean profit Fix: Recognize same long-term cost

3. Complex Outside Combinations

Mistake: Cover most of board with outside bets Problem: Complicated betting, same edge Fix: Simple bets work identically

4. Ignoring European vs American

Mistake: Play American roulette for outside bets Problem: Double the house edge Fix: Always choose European when available

Frequently Asked Questions

Are outside bets better for beginners?

Easier to understand and less volatile. You win more often but smaller amounts. Good for learning but same house edge.

Can I combine outside bets to cover more numbers?

Yes, but each bet retains its own house edge. Covering more numbers doesn't reduce expected loss percentage.

Should I use the Martingale on outside bets?

It works short-term but fails long-term. Table limits and bankroll limits eventually cause catastrophic loss. Not recommended.

Is red more likely after multiple blacks?

No. Each spin is independent. Past results don't influence future spins. This is the gambler's fallacy.

What's the best outside bet?

All have identical 2.70% house edge. Choose based on preference. If available, use La Partage tables (1.35% edge).

How often will I win on even-money bets?

About 48.65% on European roulette. Over 100 spins, expect roughly 49 wins and 51 losses on average.

Pro Tips

• European only: 2.70% beats American 5.26%

• Seek La Partage: 1.35% is best roulette edge

• Flat bet: Progressions don't beat the edge

• Session limits: Set win/loss limits

• Enjoy consistency: Outside bets for steady action

Related Calculators

• Roulette Odds Calculator - All bet types
• Roulette Column Bet Calculator - Column strategy
• Roulette Expected Value Calculator - EV analysis
• House Edge Calculator - Edge comparison
• Gambling Bankroll Calculator - Session planning

Conclusion

Outside bets offer roulette's most consistent experience—win roughly half your bets with even-money wagers. Our calculator shows the identical house edge across all bet types while highlighting why outside betting suits players seeking longer sessions and lower volatility.

Calculate Outside Bet Odds Now →

Choosing red over black or odd over even doesn't change your mathematical expectation. What changes is the experience—more frequent wins, smaller amounts, steadier bankroll. Our calculator quantifies exactly what to expect from outside betting.