Odds Calculator - Convert Betting Odds & Calculate Probability
Free odds calculator to convert betting odds, calculate implied probability, parlay odds, and expected value. Perfect for sports betting analysis.
Odds Converter
Expected Value Calculator
Your estimated probability that this bet will win
Converted Odds
Payout Calculation
Expected Value
Break-even bet. No expected profit or loss over the long run.
Profit at Different Stakes
Parlay Calculator
Combine multiple bets into a parlay. All legs must win for the parlay to pay out.
Understanding Betting Odds
American Odds
American odds use positive (+) and negative (-) numbers. Positive odds show how much profit you would make on a $100 bet. Negative odds show how much you need to bet to win $100.
- +150 means a $100 bet wins $150 profit
- -110 means you bet $110 to win $100 profit
- Higher positive numbers = bigger underdog
- Higher negative numbers = bigger favorite
Decimal Odds
Decimal odds represent the total return (stake + profit) for every $1 wagered. This format is popular in Europe and Australia.
- 2.50 odds means $1 bet returns $2.50 total
- Multiply your stake by the odds for total payout
- Subtract 1 to get profit multiplier
- Higher numbers = less likely outcome
Fractional Odds
Fractional odds show the potential profit relative to the stake. This format is traditional in UK betting markets.
- 3/2 means you win $3 for every $2 bet
- Also written as "3 to 2" or "3:2"
- 1/1 is "evens" or break-even
- Higher numerator = bigger underdog
Implied Probability
Implied probability converts odds into a percentage chance of winning. Bookmakers build in a margin (the "vig" or "juice") so the total implied probabilities exceed 100%.
- Calculate: 1 / decimal odds × 100
- Compare to your own probability assessment
- Find value when your odds are better
- Account for bookmaker margin
Advanced Betting Concepts
Expected Value (EV)
Expected value is the average amount you can expect to win or lose per bet over the long run. Positive EV bets are profitable over time, while negative EV bets will lose money.
EV = (Probability of Win × Profit) - (Probability of Loss × Stake)
Professional bettors seek positive EV opportunities by finding discrepancies between bookmaker odds and their own probability assessments. The odds calculator helps identify these value bets.
Parlay Betting
A parlay (or accumulator) combines multiple bets into one. All selections must win for the parlay to pay out, but the potential returns are much higher than individual bets.
- Higher risk, higher reward: Parlays offer larger payouts but are harder to win
- Multiplicative odds: Decimal odds are multiplied together
- Lower probability: A 2-leg parlay at 50% each has only 25% chance of winning
- Bookmaker advantage: The vig compounds across multiple legs
Tips for Using This Odds Calculator
- Compare formats: Different sportsbooks use different odds formats. Use this calculator to quickly convert between them.
- Calculate implied probability: Understand what the bookmaker thinks the probability is and compare to your own analysis.
- Find value: Use the EV calculator to identify bets where your probability assessment suggests positive expected value.
- Parlay caution: While parlays offer exciting payouts, remember that each additional leg significantly reduces your win probability.
- Bankroll management: Even positive EV bets can lose. Use proper staking strategies and never bet more than you can afford to lose.
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Disclaimer: This calculator is for educational and illustrative purposes only. Results are estimates and may not reflect actual outcomes. Investing Point does not guarantee the accuracy of these calculations and is not responsible for any decisions made based on this tool.