Most betting calculators tell you what you could win. They flash a big number: “Bet $10 to win $500!” But they don’t tell you the most important thing: What are the chances of that actually happening?
The Parlay EV Calculator is different. It doesn’t just calculate your potential payout; it calculates your Expected Value (EV). By comparing the Bookmaker’s Odds against the “True” probability of each leg winning, this tool reveals whether your accumulator is a smart investment (+EV) or a mathematical donation to the sportsbook (-EV).
Understand the “Compounding House Edge” and stop making bets that look good but perform poorly on the long run.
Parlay EV Calculator
Value AnalysisHow to Use the Calculator
To use this tool effectively, you need to think like a sharp bettor. You aren’t just inputting the odds; you are inputting your assessment of the game.
- Enter Your Stake: The total amount you are wagering.
- Add Your Legs (Selections): For each game in your parlay, input two values:
- Bookie Odds (Decimal): The price the sportsbook is giving you (e.g., 1.90 or 2.10).
- Fair Win %: This is the key. What do you think is the true probability of this team winning? Is it a coin flip (50%)? Is it a lock (80%)?
- Analyze the Results:
- True Win Probability: The actual mathematical chance of all legs winning.
- Expected Value (EV): If this number is negative (e.g., -$15), you are losing money on average for every bet you place. If it is positive, you have found a profitable edge.
Related Tools: To convert American odds (-110) to the Decimal odds used in calculations, use our Odds Converter. If you find a parlay with high +EV, determine the optimal bet size using the Kelly Criterion Calculator.
Real-World Examples: The “Parlay Tax”
Why do professionals usually avoid parlays? Because the “House Edge” compounds. Here is the math.
Example 1: The “Standard” Losing Parlay
You bet $100 on a 3-leg parlay. Every leg is a standard point spread (-110 American / 1.91 Decimal). These are essentially coin flips.
- Bookie Odds: 1.91 per leg.
- True Probability: 50% per leg.
- The Result: The calculator shows an EV of roughly -$14.00 (ROI -14%).
- The Lesson: Even though you could win big, the sportsbook is charging you a ~4.5% fee three times. The fees multiply, eating your value.
Example 2: The “Value” Parlay (+EV)
You find two games where you believe the underdog is undervalued.
- Leg 1: Odds 2.20, but you think they have a 50% chance to win.
- Leg 2: Odds 2.10, but you think they have a 52% chance to win.
- The Result: The calculator shows a massive Positive EV. Because both legs have value individually, multiplying them creates exponentially higher value (assuming the outcomes are not correlated).
Frequently Asked Questions (FAQ)
Why is my Parlay EV almost always negative?
Sportsbooks bake a margin (“Vig” or “Juice”) into every set of odds. When you combine multiple bets into a parlay, you are multiplying these margins together. Unless you are an expert at finding “Value Bets” (odds that are higher than they should be), the math works heavily against you in parlays.
How do I calculate “Fair Win %”?
This is the skill of handicapping. You can estimate it using your own models, or by looking at “Sharp” sportsbooks (like Pinnacle) and removing the vigorish (No-Vig Odds) to find the market’s true implied probability.
No. This calculator assumes each leg is an independent event (e.g., two different football games). If you bet on “Chiefs to Win” AND “Patrick Mahomes over 2.5 TDs,” those are correlated. The math for correlated parlays is much more complex and requires specific correlation data.