Learn How to Calculate Parlay Odds

Understanding Parlay Bets and Their Basic Structure

A parlay bet combines multiple individual wagers into a single bet where all selections must win for you to receive a payout. Unlike placing separate bets on each event, a parlay links them together—if even one selection loses, the entire parlay loses and you receive nothing. This structure creates the potential for larger payouts because the winnings from one bet roll over to become the stake for the next bet.

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The appeal of parlays lies in their multiplicative nature. If you place a $10 bet on two events and both win, your payout grows substantially compared to two separate $10 bets. However, this higher payout potential comes with increased risk. The more selections you add to a parlay, the lower your chances of winning because every single selection must be correct.

Parlays can include various types of bets: point spreads, moneyline bets, over/under totals, or prop bets. Some sportsbooks allow you to mix different bet types within a single parlay. The number of selections in a parlay typically ranges from two selections up to 12 or more, depending on the sportsbook. Two-team parlays are sometimes called "doubles," three-team parlays are called "trebles," and larger parlays may be called "accumulators."

Understanding parlay structure matters because it directly impacts how odds are calculated and what payout you might receive. A parlay's final odds multiply together, which is why understanding individual odds conversion becomes essential. Sports bettors often use parlays as a way to turn small stakes into larger returns, though winning consistently requires favorable results across multiple events.

Practical Takeaway: Recognize that a parlay is a linked series of bets where all selections must win. Before calculating odds, confirm that you understand which events you're including and whether your sportsbook allows your specific combination of bet types.

Converting Decimal and American Odds Formats

Sportsbooks display odds in different formats depending on their location and preference. The two most common formats in North America and Europe are decimal odds and American odds (also called moneyline odds). To calculate parlay odds accurately, you need to convert your odds into a consistent format, typically decimal odds, which makes multiplication straightforward.

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Decimal odds represent the total return for every dollar wagered, including your original stake. For example, decimal odds of 1.50 means that for every $1 you bet, you receive $1.50 total if you win—a $0.50 profit. Decimal odds are straightforward: multiply your stake by the decimal odds to find your total return. If you bet $100 at 1.50 decimal odds, you get $150 total ($100 stake plus $50 profit).

American odds, displayed with a plus or minus sign, work differently. Negative odds (like -110) show how much you need to wager to win $100. Positive odds (like +150) show how much profit you make on a $100 wager. To convert American odds to decimal odds, use these formulas:

• For negative American odds: Decimal odds = (100 / absolute value of American odds) + 1. Example: -110 converts to (100/110) + 1 = 1.909
• For positive American odds: Decimal odds = (American odds / 100) + 1. Example: +150 converts to (150/100) + 1 = 2.50

Let's examine a practical example. Suppose a sportsbook lists two teams at -110 (decimal 1.909) and +150 (decimal 2.50). To calculate the parlay odds, you would multiply these decimal odds: 1.909 × 2.50 = 4.7725. This means a $100 parlay bet would return $477.25 total if both selections win.

Practical Takeaway: Convert all odds to decimal format before multiplying for parlay calculations. Bookmark or memorize the conversion formulas so you can quickly translate the odds displayed on your sportsbook into decimals for accurate parlay calculations.

Calculating Parlay Odds: The Multiplication Method

Once you've converted your odds to decimal format, calculating parlay odds involves straightforward multiplication. Take each selection's decimal odds and multiply them together to find your combined parlay odds. This is the core calculation that determines your potential payout.

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Here's a detailed example with three selections: Suppose you want to place a three-team parlay. Team A has decimal odds of 1.80, Team B has 2.00, and Team C has 1.50. To calculate the parlay odds, multiply: 1.80 × 2.00 × 1.50 = 5.40. This means your parlay odds are 5.40. If you wagered $100, your total payout would be $540 (representing a $440 profit).

The multiplication method works the same regardless of how many selections you include. A four-team parlay with odds of 1.50, 1.70, 1.90, and 2.10 would calculate as: 1.50 × 1.70 × 1.90 × 2.10 = 10.1745. A $50 bet at these odds would return $508.73.

It's important to understand that each additional selection multiplies the previous result. This exponential growth explains why parlays with many selections offer such high payouts but become increasingly difficult to win. Adding one more -120 odds selection (decimal 1.833) to a five-team parlay dramatically increases the final odds but also decreases your probability of success proportionally.

Many bettors make the mistake of adding odds together instead of multiplying them. This is incorrect and will produce inaccurate results. For instance, with odds of 2.00 and 2.00, adding them gives 4.00, but multiplying them correctly gives 4.00 as well—which only works in this specific case. With different odds like 1.80 and 2.00, adding produces 3.80 while multiplying produces 3.60, showing the importance of using multiplication.

Practical Takeaway: Always multiply decimal odds together, never add them. Write down each selection's decimal odds, multiply them sequentially, and verify your calculation by working through it step-by-step to catch any errors.

Understanding Probability and True Odds in Parlays

Behind every parlay's odds lies probability mathematics. When you multiply odds together, you're also multiplying the implied probabilities of each selection winning. Understanding this relationship reveals why parlay payouts increase—and why winning becomes harder as you add more selections.

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To calculate implied probability from decimal odds, use this formula: Probability = 1 / decimal odds. For example, decimal odds of 2.00 imply a probability of 1/2.00 = 0.50, or 50%. Odds of 1.80 imply a probability of 1/1.80 = 0.556, or 55.6%. Odds of 1.50 imply 66.7%.

When you create a parlay, you multiply these probabilities together. Consider a two-team parlay where each team has decimal odds of 2.00 (50% implied probability). The probability of both winning is 0.50 × 0.50 = 0.25, or 25%. However, the parlay odds are 2.00 × 2.00 = 4.00, which implies a 25% probability. This alignment shows how the odds correctly reflect the reduced probability of success.

Here's a more complex example: A three-team parlay with odds of 1.80, 2.00, and 1.50. The implied probabilities are 55.6%, 50%, and 66.7% respectively. Multiplying these probabilities: 0.556 × 0.50 × 0.667 = 0.185, or 18.5%. The parlay odds (1.80 × 2.00 × 1.50 = 5.40) imply 1/5.40 = 18.5%, confir