Expected Value Calculator - Find +EV Bets
Expected Value (EV) Calculator
Expected Value Analysis
Probability Comparison
EV Breakdown
How to Use This Expected Value Calculator:
- Enter your bet amount (stake)
- Input the odds offered by the sportsbook
- Estimate your true win probability using the slider or input
- Click "Calculate EV" to see visual gauge and results
- Only bet when EV is positive (+EV) for long-term profit
What is an Expected Value Calculator?
An expected value calculator is an essential betting tool that calculates the average profit or loss you can expect from a bet over time. By comparing your estimated win probability against the odds offered by sportsbooks, the EV calculator identifies which bets offer positive expected value (+EV) and are profitable long-term.
Professional sports bettors use expected value as their primary metric for finding profitable bets. Whether you're betting on NFL games, NBA spreads, or MLB moneylines, understanding EV is crucial for consistent profitability. Our calculator makes it simple to determine if any bet offers value with visual indicators.
How to Calculate Expected Value (EV Formula)
The expected value formula determines your average profit or loss per bet:
Expected Value Formula for Betting
Where:
• Probability of Winning = Your estimated probability (not the implied odds)
• Amount Won = Profit if bet wins
• Probability of Losing = 1 - Probability of Winning
• Amount Lost = Your stake
Expected Value Calculator Example
Let's calculate EV for a real betting scenario:
- Bet: $100 on underdog at +150 odds
- Your estimated win probability: 45%
- Profit if win: $150
- Loss if lose: $100
Calculation:
EV = (0.45 × $150) - (0.55 × $100)
EV = $67.50 - $55.00
EV = +$12.50
This positive EV of $12.50 means you expect to profit $12.50 on average per $100 bet over time.
Understanding Positive vs Negative Expected Value
Positive Expected Value (+EV)
| +EV Indicators | What It Means | Action |
|---|---|---|
| EV > 0 | Profitable long-term | BET |
| Your prob > Implied prob | Edge over bookmaker | BET |
| EV% > 2% | Strong value | BET MORE |
Negative Expected Value (-EV)
| -EV Indicators | What It Means | Action |
|---|---|---|
| EV < 0 | Losing bet long-term | PASS |
| Your prob < Implied prob | No edge | PASS |
| EV% < -5% | Terrible value | AVOID |
Expected Value Calculator for Different Sports
NFL Expected Value Example
Finding +EV bets in NFL point spreads:
| Bet Type | Odds | Market Prob | Your Prob | EV per $100 |
|---|---|---|---|---|
| Chiefs -3.5 | -110 | 52.38% | 56% | +$1.82 |
| Over 48.5 | -105 | 51.22% | 48% | -$6.48 |
| Bills ML | +180 | 35.71% | 40% | +$12.00 |
NBA Expected Value Betting
Common +EV spots in NBA betting:
- Player props: Books often misprice based on recent performance
- Live betting: In-game momentum creates value opportunities
- Back-to-backs: Fatigue factors often undervalued by public
- Injury news: Quick reactions beat line movements
MLB Underdog Value
Baseball underdogs frequently offer +EV due to variance:
| Scenario | Typical Odds | True Win % | Average EV |
|---|---|---|---|
| Home dog vs ace | +170 | 38-40% | +2-4% |
| Division rival dog | +140 | 42-44% | +1-3% |
| Day game after night | +155 | 40-42% | +2-4% |
How to Find Your True Win Probability
The key to using an expected value calculator effectively is accurately estimating win probability:
1. Statistical Models
- Use advanced metrics (EPA, DVOA, xG, etc.)
- Build or follow proven prediction models
- Adjust for situational factors
- Track your estimation accuracy
2. Market Comparison
- Compare odds across multiple sportsbooks
- Sharp books (Pinnacle) indicate true probability
- Line movement reveals smart money
- Closing line value validates estimates
3. Information Edges
- Injury reports before public
- Weather impacts (wind, temperature)
- Motivation factors (playoffs, rivalry)
- Rest and travel considerations
Expected Value and Bankroll Management
Once you find +EV bets, proper staking maximizes long-term growth:
Kelly Criterion for EV Betting
The Kelly Criterion suggests betting a percentage of bankroll based on edge:
Example: 5% edge at +150 odds
Kelly % = (0.05 × 2.5) / 1.5 = 8.33% of bankroll
Conservative Staking for +EV Bets
| EV Range | Full Kelly | Half Kelly | Quarter Kelly |
|---|---|---|---|
| 0-2% | 0-3% | 0-1.5% | 0-0.75% |
| 2-5% | 3-8% | 1.5-4% | 0.75-2% |
| 5%+ | 8%+ | 4%+ | 2%+ |
Common Expected Value Mistakes
1. Overestimating Win Probability
- Bias toward favorite teams
- Recency bias from last game
- Ignoring regression to mean
- Not accounting for vig in estimates
2. Small Sample Size
- EV is a long-term concept
- Variance affects short-term results
- Need 1000+ bets to validate edge
- Track closing line value (CLV)
3. Not Shopping for Best Odds
Same bet can have different EV at different books:
| Sportsbook | Odds | EV at 42% Win |
|---|---|---|
| Book A | +130 | -$3.40 |
| Book B | +140 | +$0.80 |
| Book C | +145 | +$2.90 |
Frequently Asked Questions
What is an expected value calculator?
An expected value calculator is a betting tool that calculates the average profit or loss you can expect from a bet over time. It uses your estimated win probability and the odds offered to determine if a bet has positive expected value (+EV) or negative expected value (-EV). Positive EV bets are profitable long-term.
How do you calculate expected value in betting?
Expected value formula: EV = (Probability of Winning × Amount Won) - (Probability of Losing × Amount Lost). For a $100 bet at +150 odds with 45% win probability: EV = (0.45 × $150) - (0.55 × $100) = $67.50 - $55 = +$12.50. This positive EV indicates a profitable bet long-term.
What is a good expected value in sports betting?
Any positive expected value (+EV) is good in sports betting, as it indicates long-term profitability. Professional bettors typically look for edges of 2-5% or higher. An EV of +5% means you expect to profit $5 for every $100 wagered over time. Even small edges compound significantly with volume.
How accurate should my win probability estimate be?
Your win probability estimate should be as accurate as possible, as EV calculations depend entirely on this input. Use statistical models, compare odds across sharp books, track your estimation accuracy over time, and adjust for factors like injuries, weather, and motivation. Even being off by 2-3% can turn a +EV bet into -EV.
What's the difference between EV and ROI?
Expected Value (EV) is the average profit per bet in dollars, while Return on Investment (ROI) is the percentage return on your stake. For a $100 bet with +$5 EV, the ROI is 5%. EV tells you how much you'll make, ROI tells you the efficiency of your betting. Both metrics are important for bankroll management.
Should I only bet when EV is positive?
Yes, professional bettors only place bets with positive expected value. Negative EV bets will lose money over time, regardless of short-term results. Focus on finding and betting only +EV opportunities, use proper bankroll management, and track your results to verify your edge over a large sample size.
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- Implied Probability Calculator - Convert odds to probabilities
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