Most sports bettors view parlays (accumulators) as lottery tickets—small stakes for massive payouts, with little expectation of winning. Sportsbooks love this because the “Vig” (house edge) usually compounds with every leg you add, making it mathematically nearly impossible to win long-term.
But what if you have an edge?
If you identify bets where the probability of winning is higher than what the odds imply, a parlay can actually be a powerful tool to multiply your edge. Our Parlay EV Calculator allows you to input your own handicapping percentages against the bookmaker’s odds to determine if the total wager offers positive Expected Value (+EV).
Parlay EV Calculator
Value AnalysisHow to Use the Parlay EV Calculator
This tool compares the Price You are Getting (Bookie Odds) vs. the True Chance of Winning (Your Probability).
- Add Legs: Click “+ Add Leg” for as many events as are in your parlay.
- Enter Bookie Odds: Input the decimal odds offered by the sportsbook (e.g., 1.91).
- Note: If you use American odds, use our Odds Converter first.
- Enter Your Win Probability (%): This is the most critical step. Enter the percentage chance you believe the bet has of winning.
- Tip: If you believe a bet is a “Coin Flip,” enter 50%. If you think a team is a heavy favorite, enter 70% or 80%.
- Analyze the Results:
- True Odds: The mathematical odds based on your probabilities.
- Expected Value (EV): If this is Positive (Green), the bet is profitable in the long run. If Negative (Red), you are losing value.
- Kelly Stake: The recommended percentage of your bankroll to wager based on the edge.
Related Tools: If you simply want to see the payout of a parlay without analyzing value, use the standard Parlay Calculator. If your legs are correlated (e.g., Same Game Parlay), use the Multi-Event Probability Calculator to adjust for correlation.
Real-World Examples: Sucker Bet vs. Value Bet
The difference between a “Square” (amateur) and a “Sharp” (pro) is often just a few percentage points of probability.
Example 1: The “Standard” Parlay (-EV)
You bet a 2-leg parlay on two NFL spreads. The bookie offers 1.91 (-110) on both. You believe both games are perfect coin flips (50% chance).
- Bookie Odds: 3.65.
- True Probability: 25% (0.50 × 0.50).
- EV: -8.8%.
- Verdict: This is a bad bet. The house edge has compounded, and you are losing nearly 9 cents on every dollar wagered.
Example 2: The “Sharp” Parlay (+EV)
You find two mispriced lines. The bookie offers 2.00 (+100) on two underdogs. However, your handicapping model suggests they actually have a 53% chance to win each.
- Bookie Odds: 4.00.
- True Probability: 28.09% (0.53 × 0.53).
- EV: +12.36%.
- Verdict: Because you have an edge on each individual leg, the parlay multiplies that edge. This is a highly profitable value bet.
Frequently Asked Questions (FAQ)
Can I use this for Same Game Parlays (SGP)?
No. This calculator assumes that all events are independent (the result of one does not affect the other). In an SGP (e.g., “Team A to Win” and “Quarterback A to throw 2 TDs”), the events are correlated. Using this calculator for SGPs will result in incorrect probability calculations.
What is “Break-Even Probability”?
This is the minimum probability required for your bet to result in zero profit/loss over time. If your estimated “True Probability” is higher than the “Break-Even Probability,” the bet has positive expected value (+EV).
Should I bet the Full Kelly amount?
Most professionals recommend betting Fractional Kelly (usually 1/4 or 1/2 Kelly). Parlays have high variance (low win rate), and betting Full Kelly can lead to massive bankroll swings. Fractional Kelly reduces risk while still growing your bankroll.