Sports Betting Bankroll Calculator: Protect Your Money

Bankroll management separates recreational bettors who go broke from serious bettors who survive variance. Our free calculator helps you size bets appropriately, track your bankroll, and build sustainable betting habits.

What Is Bankroll Management?

Bankroll management means determining how much money to dedicate to betting and how much to wager on each bet. Proper management protects against variance and prevents devastating losses.

Quick Answer: Most professionals recommend risking 1-3% of your bankroll per bet. With a $1,000 bankroll, that's $10-30 per wager. This sizing lets you survive losing streaks while still having meaningful action.

How to Use Our Free Bankroll Calculator

Use the Sports Betting Bankroll Calculator →

Enter your bankroll and parameters to get optimal bet sizing.

Step-by-Step Instructions

1. Enter Total Bankroll: Money dedicated to betting

2. Set Risk Percentage: How much to risk per bet (1-5%)

3. Input Expected Win Rate: Your historical or expected accuracy

4. View Recommendations: Optimal unit size and ruin probability

Input Fields Explained

Field	Description	Example
Bankroll	Total betting funds	$2,000
Risk per Bet	Percentage wagered	2%
Unit Size	Dollar amount per bet	$40
Win Rate	Expected accuracy	53%
Ruin Probability	Chance of going broke	2.3%

Unit Betting System

What Is a Unit?

A unit is a standardized bet size—typically 1-2% of your bankroll:

Bankroll	1% Unit	2% Unit
$500	$5	$10
$1,000	$10	$20
$2,500	$25	$50
$5,000	$50	$100
$10,000	$100	$200

Why Use Units?

1. Consistency: Same relative risk on every bet
2. Scalability: Units adjust as bankroll changes
3. Tracking: Measure profit in units, not dollars
4. Comparison: Compare results across different bankrolls

Adjusting Unit Size

Recalculate units when bankroll changes significantly:

• Up 20%+: Increase unit size
• Down 20%+: Decrease unit size
• Review monthly: Regular recalibration

Risk Percentage Guidelines

Conservative (1% per bet)

Best for:

• New bettors learning
• High-variance betting (props, futures)
• Risk-averse personalities

Example: $1,000 bankroll × 1% = $10 bets

Standard (2% per bet)

Best for:

• Experienced bettors
• -110 spread/total betting
• Moderate risk tolerance

Example: $1,000 bankroll × 2% = $20 bets

Aggressive (3-5% per bet)

Best for:

• Proven profitable track record
• Strong edge on specific bets
• Higher risk tolerance

Example: $1,000 bankroll × 3% = $30 bets

Warning: Above 5% dramatically increases ruin probability.

Probability of Ruin

What Is Ruin?

"Ruin" means losing your entire bankroll. Proper sizing minimizes this risk.

Ruin Probability by Bet Size

Assuming 52.4% win rate at -110:

Bet Size	500-Bet Ruin Risk
1%	<0.1%
2%	~1%
3%	~5%
5%	~15%
10%	~40%

At 10% per bet, you're gambling with your bankroll's life.

Factors Affecting Ruin

• Win rate: Higher = lower ruin risk
• Bet size: Larger = higher ruin risk
• Odds: Longer odds = higher variance = higher ruin risk
• Number of bets: More bets = more exposure to variance

Real-World Bankroll Examples

Example 1: Recreational Bettor

Profile:

• Bankroll: $500
• Goals: Entertainment, learn betting
• Experience: Beginner

Recommendation:

• Unit size: 1% = $5
• Bets per week: 5-10
• Monthly exposure: ~$200-400
• Ruin risk: Very low

Example 2: Serious Amateur

Profile:

• Bankroll: $2,500
• Goals: Profitable hobby
• Experience: 1-2 years, breakeven

Recommendation:

• Unit size: 2% = $50
• Bets per week: 10-20
• Track all bets meticulously
• Review and adjust monthly

Example 3: Aspiring Professional

Profile:

• Bankroll: $10,000
• Goals: Supplemental income
• Experience: Proven 54%+ win rate

Recommendation:

• Unit size: 1-2% = $100-200
• Multiple sportsbook accounts
• Kelly Criterion for edge-based sizing
• Strict discipline

Kelly Criterion for Advanced Sizing

What Is Kelly Criterion?

Kelly optimizes bet size based on your edge:

Kelly % = (bp - q) / b

Where:

• b = decimal odds - 1
• p = win probability
• q = lose probability (1 - p)

Example Calculation

Bet: -110 odds (1.909 decimal) Your estimated edge: 54% win probability

b = 1.909 - 1 = 0.909
p = 0.54
q = 0.46

Kelly = (0.909 × 0.54 - 0.46) / 0.909
Kelly = (0.491 - 0.46) / 0.909
Kelly = 3.4%

Full Kelly suggests 3.4% bet size.

Fractional Kelly

Most bettors use 1/4 to 1/2 Kelly:

• Full Kelly: Highest growth, highest variance
• Half Kelly: 75% of growth, much lower variance
• Quarter Kelly: Safest growth, very low variance

Common Bankroll Mistakes

1. Betting Too Large

Problem: 10%+ of bankroll per bet Result: Quick ruin during losing streaks Fix: Cap at 3%, preferably 1-2%

2. Chasing Losses

Problem: Doubling up after losses Result: Accelerated ruin, emotional betting Fix: Flat betting, take breaks after losses

3. No Dedicated Bankroll

Problem: Betting from checking account Result: No tracking, can't assess performance Fix: Separate betting fund, track every bet

4. Moving Up Too Fast

Problem: Increasing units after small samples Result: Overexposure during reversion Fix: Need 500+ bet sample before increasing

5. Ignoring Variance

Problem: Expecting smooth profit curve Result: Emotional decisions during downswings Fix: Understand that 10-bet losing streaks happen

Frequently Asked Questions

How much bankroll do I need to start?

Whatever you can afford to lose completely. Start with $100-500 for recreation, $1,000+ if serious about learning.

Should I ever bet more than 5%?

Rarely. Only if you have a massive, proven edge on a specific bet—and even then, half-Kelly is safer.

How do I handle a losing streak?

Keep bet sizes the same (in percentage terms). Don't chase. Take a day off if emotional.

When should I increase my unit size?

After 500+ bets with proven positive ROI, and only if bankroll has grown 20%+ from starting point.

What if I can't afford to lose my bankroll?

Don't bet. Gambling should only use discretionary money you're prepared to lose entirely.

How do professionals manage bankroll?

1-2% per bet, multiple sportsbooks, detailed tracking, regular performance review, Kelly-based sizing for edge bets.

Bankroll Growth Simulation

Expected Growth Over Time

With 54% win rate, 2% bet size, -110 odds:

Bets	Expected Bankroll Growth
100	+4%
500	+21%
1,000	+48%
2,500	+150%

Note: Actual results vary significantly due to variance.

Variance Reality Check

Even with edge, expect:

• 10+ bet losing streaks
• Months of breakeven or loss
• Drawdowns of 15-25% of bankroll

Proper sizing lets you survive these to reach long-term expectation.

Tracking Your Bankroll

What to Track

Data Point	Purpose
Date	Timing patterns
Sport/League	Performance by sport
Bet type	Spread vs. total vs. ML
Odds	Line value analysis
Stake	Position sizing
Result	Win/loss/push
Profit/Loss	Running total

Review Frequency

• Daily: Update tracker
• Weekly: Review week's performance
• Monthly: Analyze by sport, bet type
• Quarterly: Major strategy review

Pro Tips for Bankroll Management

• Separate your bankroll: Don't mix with living expenses

• Track everything: Can't improve what you don't measure

• Flat bet initially: Learn before variable sizing

• Survive to thrive: Bankroll preservation > quick profits

• Be honest: Include all bets, even embarrassing losses

Related Calculators

• Kelly Criterion Calculator - Optimal bet sizing
• Sports Betting ROI Calculator - Performance tracking
• Expected Value Calculator - Per-bet analysis
• Hedge Calculator - Lock in profits
• Odds Converter - Compare odds formats

Conclusion

Bankroll management is the foundation of sustainable betting. Our calculator helps you determine proper unit sizes, understand ruin probability, and build responsible betting habits. Without proper money management, even winning bettors go broke—don't let that be you.

Calculate Your Optimal Bankroll Now →

Protect your bankroll, and you protect your ability to bet long-term. Size your bets appropriately, track everything, and let the math work in your favor over time.