Calculating Betting Odds

Betting Odds Converter & Payout Calculator

Use this calculator to convert between different betting odds formats (Decimal, Fractional, American), calculate the implied probability of an event, and determine your potential payout based on your stake.

Decimal Fractional American

function toggleFractionalDenominator() { var format = document.getElementById('oddsFormatSelect').value; var fractionalGroup = document.getElementById('fractionalDenominatorGroup'); if (format === 'fractional') { fractionalGroup.style.display = 'block'; } else { fractionalGroup.style.display = 'none'; } } function calculateOdds() { var oddsValue = parseFloat(document.getElementById('oddsValueInput').value); var oddsFormat = document.getElementById('oddsFormatSelect').value; var fractionalDenominator = parseFloat(document.getElementById('fractionalDenominatorInput').value); var stakeAmount = parseFloat(document.getElementById('stakeAmountInput').value); document.getElementById('decimalOddsResult').innerHTML = "; document.getElementById('fractionalOddsResult').innerHTML = "; document.getElementById('americanOddsResult').innerHTML = "; document.getElementById('impliedProbabilityResult').innerHTML = "; document.getElementById('potentialPayoutResult').innerHTML = "; if (isNaN(oddsValue) || oddsValue <= 0) { alert('Please enter a valid positive odds value.'); return; } if (oddsFormat === 'fractional' && (isNaN(fractionalDenominator) || fractionalDenominator <= 0)) { alert('Please enter a valid positive fractional denominator.'); return; } if (isNaN(stakeAmount) || stakeAmount 0) { decimalOdds = (oddsValue / 100) + 1; } else { decimalOdds = (100 / Math.abs(oddsValue)) + 1; } } var fractionalNumeratorPart = decimalOdds – 1; var fractionalResult = "; if (fractionalNumeratorPart > 0) { var tolerance = 1.0E-6; var h1 = 1, h2 = 0, k1 = 0, k2 = 1; var b = fractionalNumeratorPart; do { var a = Math.floor(b); var aux = h1; h1 = a * h1 + h2; h2 = aux; aux = k1; k1 = a * k1 + k2; k2 = aux; b = 1 / (b – a); } while (Math.abs(b – Math.floor(b)) > tolerance && k1 = 2.00) { americanResult = '+' + Math.round((decimalOdds – 1) * 100); } else { americanResult = '-' + Math.round(100 / (decimalOdds – 1)); } var impliedProbability = (1 / decimalOdds) * 100; var potentialPayout = stakeAmount * decimalOdds; document.getElementById('decimalOddsResult').innerHTML = decimalOdds.toFixed(2); document.getElementById('fractionalOddsResult').innerHTML = fractionalResult; document.getElementById('americanOddsResult').innerHTML = americanResult; document.getElementById('impliedProbabilityResult').innerHTML = impliedProbability.toFixed(2) + '%'; document.getElementById('potentialPayoutResult').innerHTML = '$' + potentialPayout.toFixed(2); } window.onload = function() { toggleFractionalDenominator(); calculateOdds(); };

Understanding Betting Odds

Betting odds represent the probability of an event occurring and determine the potential payout for a winning bet. They are a fundamental concept in sports betting and other forms of wagering. Understanding how to read and convert different odds formats is crucial for making informed betting decisions.

Types of Betting Odds

There are three primary formats for displaying betting odds:

1. Decimal Odds (European Odds):

   Decimal odds are the most straightforward format, commonly used in Europe, Canada, and Australia. They represent the total return for every $1 (or unit) wagered, including your initial stake. For example, if the decimal odds are 2.50, a $10 bet would return $25 ($10 stake + $15 profit).

   Calculation: Total Payout = Stake × Decimal Odds

   Implied Probability: (1 / Decimal Odds) × 100%

2. Fractional Odds (Traditional Odds / UK Odds):

   Fractional odds are popular in the UK and Ireland. They represent the profit you will receive relative to your stake. For example, odds of 3/2 (read as "three to two") mean that for every $2 you bet, you will win $3 in profit, plus your original $2 stake back, for a total return of $5.

   Calculation: Profit = Stake × (Numerator / Denominator)

   Total Payout: Stake + Profit

   Conversion to Decimal: (Numerator / Denominator) + 1

3. American Odds (Moneyline Odds):

   American odds are primarily used in the United States. They are displayed with a plus (+) or minus (-) sign, indicating whether you need to bet to win $100 or how much you win for a $100 bet.

   • Negative Odds (-): Indicate the favorite. The number shows how much you need to wager to win $100 profit. E.g., -200 means you must bet $200 to win $100 profit (total return $300).
   • Positive Odds (+): Indicate the underdog. The number shows how much profit you will win for a $100 wager. E.g., +150 means a $100 bet will win $150 profit (total return $250).

   Conversion to Decimal:

   • If American Odds > 0: (American Odds / 100) + 1
   • If American Odds < 0: (100 / |American Odds|) + 1

Implied Probability

Implied probability is the likelihood of an outcome suggested by the betting odds. It's calculated by converting the odds into a percentage. For example, decimal odds of 2.00 imply a 50% chance (1/2.00 = 0.50 = 50%). This percentage does not account for the bookmaker's margin (vig or overround), which means the sum of implied probabilities for all outcomes in an event will typically exceed 100%.

Potential Payout

The potential payout is the total amount you would receive if your bet wins, including your original stake. It's a simple calculation once you have the decimal odds and your stake amount.

How to Use the Calculator

1. Enter Odds Value: Input the numerical value of the odds you want to convert.
2. Select Odds Format: Choose whether the odds you entered are Decimal, Fractional, or American.
3. Fractional Denominator (if applicable): If you selected 'Fractional', enter the denominator (e.g., for 3/2, enter '2').
4. Enter Stake Amount: Input the amount of money you wish to bet.
5. Click "Calculate Odds": The calculator will instantly display the equivalent odds in all three formats, the implied probability, and your potential payout.

Examples:

• Decimal Odds 2.50 with a $10 Stake:
  • Fractional: 3/2
  • American: +150
  • Implied Probability: 40.00%
  • Potential Payout: $25.00
• Fractional Odds 5/1 with a $20 Stake:
  • Decimal: 6.00
  • American: +500
  • Implied Probability: 16.67%
  • Potential Payout: $120.00
• American Odds -150 with a $50 Stake:
  • Decimal: 1.67
  • Fractional: 2/3
  • Implied Probability: 60.00%
  • Potential Payout: $83.33