Odds Calculator & Converter

Calculate your betting payouts and convert between American, Decimal, and Fractional odds formats

Bet Amount ($)

American Odds

Decimal Odds

Fractional Odds

Implied Probability (%)

Your Results

To Win

$0.00

Total Payout

$0.00

Implied Probability

How to Use This Odds Calculator

Getting started with our odds calculator is straightforward. You only need to input two pieces of data: your bet amount and the odds in any format you prefer. The calculator automatically converts between all formats and shows you exactly what you stand to win.

Step-by-Step Guide

Choose your bet type: Select between Single Bet or Parlay at the top of the calculator.
Enter your stake: Input how much money you want to risk on this bet.
Input odds: Enter odds in any format – American (+120, -150), Decimal (2.20, 1.67), or Fractional (6/5, 2/3). The rest converts automatically.
Review results: Check your potential profit, total payout, and the implied probability of your bet winning.

For parlays, simply add multiple legs by clicking “Add Another Leg” and input the odds for each selection. The calculator multiplies all odds together to show your combined payout.

Breaking Down Odds Formats

American Odds Explained

American odds revolve around $100 as the baseline. Positive numbers show profit on a $100 bet, while negative numbers show how much you need to bet to win $100.

Example: At +150 odds, a $100 bet wins you $150 profit. At -150 odds, you need to bet $150 to win $100 profit.

Decimal Odds Made Simple

Decimal odds represent your total return per dollar wagered, including your original stake. These are popular in Europe, Canada, and Australia because they’re straightforward to calculate.

Total Payout = Stake × Decimal Odds

Example: A $50 bet at 2.50 decimal odds returns $125 total ($50 × 2.50), which includes your $50 stake plus $75 profit.

Fractional Odds Demystified

Traditional British bookmakers use fractional odds. The fraction shows profit relative to your stake. Read it as “profit/stake” – you win the numerator for every amount equal to the denominator that you bet.

Example: At 5/2 odds, you win $5 for every $2 wagered. A $20 bet returns $50 profit plus your $20 back, totaling $70.

American	Decimal	Fractional	Implied Probability
-110	1.91	10/11	52.38%
+100	2.00	1/1	50.00%
+150	2.50	3/2	40.00%
+200	3.00	2/1	33.33%
-200	1.50	1/2	66.67%

What Is Implied Probability?

Implied probability converts betting odds into a percentage that represents the likelihood of an outcome according to the sportsbook. This metric is crucial for identifying value bets.

When a sportsbook sets odds at -110 for both sides of a game, each side has an implied probability of 52.38%. Notice that these percentages add up to more than 100% – that extra percentage represents the book’s margin, also called the vigorish or “vig.”

Finding Value Bets

The real power of implied probability comes when you compare it against your own assessment of an outcome’s likelihood. If you believe a team has a 60% chance of winning, but the implied probability is only 50%, that’s a value bet worth considering.

Real Scenario: The sportsbook offers +250 on an underdog, which equals 28.57% implied probability. Your analysis suggests this team actually has a 35% chance to win. The difference between 35% and 28.57% represents your edge.

Calculating Implied Probability

For positive American odds: Implied Probability = 100 / (Odds + 100)

For negative American odds: Implied Probability = (-Odds) / (-Odds + 100)

For decimal odds: Implied Probability = 1 / Decimal Odds

Parlay Betting Strategies

Parlays combine multiple bets into one ticket, requiring all selections to win for the bet to pay out. While they offer bigger payouts, they’re also riskier since one loss ruins the entire ticket.

How Parlay Odds Multiply

Parlay payouts multiply because you’re essentially rolling your winnings from one bet into the next. A two-leg parlay with both legs at +100 doesn’t pay +200 – it pays +300 because you’re betting your initial stake plus the profit from the first leg on the second leg.

Two-Team Parlay Example: You bet $100 on two teams, each at -110 (1.91 decimal). Your parlay odds are 1.91 × 1.91 = 3.65 decimal, or about +265 American. Your total payout would be $365 ($265 profit + $100 stake).

Common Parlay Mistakes

Many bettors get excited by the large potential payouts without considering the decreased win probability. A five-leg parlay where each leg has a 50% chance of winning only has a 3.125% chance of all five hitting (0.5^5).

Another pitfall is combining correlated outcomes. Betting on a team to win and the total to go over might seem like two separate bets, but if the team wins by scoring heavily, these outcomes are connected. Many sportsbooks prohibit certain correlated parlays.

Frequently Asked Questions

What does +200 odds mean?

Odds of +200 mean you’ll win $200 profit for every $100 wagered. If you bet $50 at +200, you’d win $100 profit ($50 × 2), plus get your $50 back for a total return of $150.

What does -150 odds mean?

Negative odds show how much you need to bet to win $100. At -150, you must risk $150 to win $100 profit. This format indicates the favorite in a matchup. Your total return on a $150 bet would be $250 ($100 profit + $150 stake).

How do I convert American odds to decimal?

For positive American odds, divide by 100 and add 1. For example, +150 becomes (150/100) + 1 = 2.50. For negative odds, divide 100 by the absolute value and add 1. So -150 becomes (100/150) + 1 = 1.67.

Why do both sides of a bet have implied probability over 50%?

Sportsbooks build in their profit margin by setting odds so that the implied probabilities add up to more than 100%. For instance, if both sides are -110, each has 52.38% implied probability, totaling 104.76%. That extra 4.76% represents the book’s edge.

Can I mix different odds formats in a parlay?

Yes! While different sportsbooks display odds in different formats, you can combine any bets into a parlay. Our calculator handles the conversion automatically – just select the format for each leg and enter the odds value.

What’s the difference between “To Win” and “Total Payout”?

“To Win” shows only your profit – the amount you gain if your bet succeeds. “Total Payout” includes both your profit and your original stake returned. So a $100 bet at +100 shows $100 to win and $200 total payout.

Are parlays worth betting?

Parlays offer entertaining action and bigger payouts but are mathematically less favorable than individual bets. The sportsbook’s edge compounds with each additional leg. They’re best used for entertainment rather than as a primary betting strategy. If you do bet parlays, keep them to 2-3 legs for a better chance of winning.

How accurate is implied probability?

Implied probability reflects what the sportsbook thinks plus their built-in margin. It’s not a perfect prediction of actual outcomes. Sharp bettors compare implied probability against their own research to find discrepancies where they have an edge.

Advanced Concepts for Serious Bettors

Line Shopping and Its Impact

Different sportsbooks offer different odds on the same games. The difference between -110 and -105 might seem small, but over hundreds of bets, it significantly impacts your profitability. A bettor who consistently gets -105 instead of -110 saves roughly $4.50 per $100 wagered.

The True Cost of Vigorish

When both sides of a bet are -110, you need to win 52.38% of your bets just to break even. This means you’re essentially paying a 4.76% fee to place your bet. Over time, this edge grinds down your bankroll unless you’re finding genuine value in your selections.

Expected Value in Sports Betting

Expected value (EV) combines your assessment of win probability with the potential payout. A positive EV bet has a higher true probability of winning than the implied probability suggests. Even positive EV bets lose sometimes, but over many bets, they’re profitable.

EV Calculation: You believe a team has a 45% chance to win at +150 odds. Your expected value is (0.45 × $150) – (0.55 × $100) = $67.50 – $55 = +$12.50 per $100 wagered. This is a bet worth taking repeatedly.

Bankroll Management Principles

Even with positive EV bets, poor bankroll management leads to ruin. Most experts recommend risking 1-5% of your bankroll per bet, with the percentage based on your confidence level. Never chase losses by increasing bet sizes – this is the fastest path to depleting your funds.

Common Calculation Errors to Avoid

Confusing Profit with Payout

A frequent mistake is misinterpreting what odds represent. When you see +200, that’s your profit, not your total return. Your actual return includes your original stake. Always check whether you’re looking at profit or total payout.

Fractional Odds Misreading

New bettors sometimes flip fractional odds. Remember that 5/2 means you win 5 units for every 2 units bet, not the other way around. The numerator is always your profit for the amount shown in the denominator.

Ignoring Decimal Precision

Small differences in decimal odds matter more than they appear. The difference between 1.90 and 1.91 is small per bet, but across hundreds of wagers, it adds up. Always use the exact decimal odds rather than rounding.

Parlay Probability Misconceptions

Some bettors assume that if they usually win 2 out of 3 bets, a three-team parlay should hit about one-third of the time. This isn’t how probability works. If each individual bet has a 66.7% win rate, the parlay only wins 29.6% of the time (0.667^3).