Bookmakers Odds Calculator
Use this calculator to understand the implied probability of an outcome, calculate your potential payout and profit from a bet, and determine the bookmaker's margin (overround) for a market.
Results:
Outcome 1:
' + 'Implied Probability: ' + impliedProb1.toFixed(2) + '%' + 'Potential Payout: $' + payout1.toFixed(2) + '' + 'Potential Profit: $' + profit1.toFixed(2) + ''; totalImpliedProbability += (1 / odds1); validOddsCount++; } else { resultOutcome1Div.innerHTML = 'Please enter valid decimal odds for Outcome 1 (e.g., 2.00).'; } // Calculate for Outcome 2 if (!isNaN(odds2) && odds2 >= 1.01) { var impliedProb2 = (1 / odds2) * 100; var payout2 = stake * odds2; var profit2 = payout2 – stake; resultOutcome2Div.innerHTML = 'Outcome 2:
' + 'Implied Probability: ' + impliedProb2.toFixed(2) + '%' + 'Potential Payout: $' + payout2.toFixed(2) + '' + 'Potential Profit: $' + profit2.toFixed(2) + ''; totalImpliedProbability += (1 / odds2); validOddsCount++; } else if (document.getElementById('oddsOutcome2').value !== ") { // Only show error if user tried to enter something invalid resultOutcome2Div.innerHTML = 'Please enter valid decimal odds for Outcome 2, or leave blank.'; } // Calculate for Outcome 3 if (!isNaN(odds3) && odds3 >= 1.01) { var impliedProb3 = (1 / odds3) * 100; var payout3 = stake * odds3; var profit3 = payout3 – stake; resultOutcome3Div.innerHTML = 'Outcome 3:
' + 'Implied Probability: ' + impliedProb3.toFixed(2) + '%' + 'Potential Payout: $' + payout3.toFixed(2) + '' + 'Potential Profit: $' + profit3.toFixed(2) + ''; totalImplliedProbability += (1 / odds3); validOddsCount++; } else if (document.getElementById('oddsOutcome3').value !== ") { // Only show error if user tried to enter something invalid resultOutcome3Div.innerHTML = 'Please enter valid decimal odds for Outcome 3, or leave blank.'; } // Calculate Overround (Bookmaker's Margin) if (validOddsCount >= 2) { // Overround is meaningful for at least two outcomes var overround = (totalImpliedProbability – 1) * 100; if (overround > 0) { resultOverroundDiv.innerHTML = 'Market Analysis:
' + 'Total Implied Probability: ' + (totalImpliedProbability * 100).toFixed(2) + '%' + 'Bookmaker\'s Overround (Margin): ' + overround.toFixed(2) + '%'; } else { resultOverroundDiv.innerHTML = 'Market Analysis:
' + 'Total Implied Probability: ' + (totalImpliedProbability * 100).toFixed(2) + '%' + 'Bookmaker\'s Overround (Margin): 0.00% (or less, indicating a value bet opportunity if total implied probability is below 100%)'; } } else if (validOddsCount === 1) { resultOverroundDiv.innerHTML = 'Enter at least two outcomes to calculate the Bookmaker\'s Overround.'; } } .bookmakers-odds-calculator { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; background-color: #f9f9f9; padding: 20px; border-radius: 8px; box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1); max-width: 600px; margin: 20px auto; border: 1px solid #e0e0e0; } .bookmakers-odds-calculator h2 { color: #333; text-align: center; margin-bottom: 20px; font-size: 24px; } .bookmakers-odds-calculator p { color: #555; line-height: 1.6; margin-bottom: 15px; } .calculator-form .form-group { margin-bottom: 15px; } .calculator-form label { display: block; margin-bottom: 5px; color: #444; font-weight: bold; } .calculator-form input[type="number"] { width: calc(100% – 22px); padding: 10px; border: 1px solid #ccc; border-radius: 4px; font-size: 16px; box-sizing: border-box; } .calculator-form button { background-color: #007bff; color: white; padding: 12px 20px; border: none; border-radius: 4px; cursor: pointer; font-size: 18px; width: 100%; box-sizing: border-box; transition: background-color 0.3s ease; } .calculator-form button:hover { background-color: #0056b3; } .calculator-results { margin-top: 25px; border-top: 1px solid #eee; padding-top: 20px; } .calculator-results h3 { color: #333; margin-bottom: 15px; font-size: 20px; text-align: center; } .calculator-results .result-item { background-color: #e9f7ef; border: 1px solid #d4edda; border-radius: 5px; padding: 15px; margin-bottom: 10px; color: #155724; } .calculator-results .result-item h4 { color: #0056b3; margin-top: 0; margin-bottom: 10px; font-size: 18px; } .calculator-results .result-item p { margin: 5px 0; font-size: 16px; } .calculator-results .result-item strong { color: #000; } .calculator-results .result-item p[style*="color: red"] { font-weight: bold; }Understanding Bookmaker Odds and Their Implications
Bookmaker odds are a fundamental aspect of sports betting, representing the likelihood of a particular outcome as perceived by the bookmaker. They also determine the potential payout for a successful bet. While odds can be presented in various formats (Decimal, Fractional, American), this calculator focuses on Decimal Odds, which are widely used for their simplicity in calculation.
What are Decimal Odds?
Decimal odds (also known as European odds) represent the total return for every $1 staked, including your original stake. For example, if the decimal odds are 2.50, a $10 bet would return $25 ($10 stake + $15 profit).
Implied Probability
One of the most crucial insights derived from bookmaker odds is the "implied probability." This is the bookmaker's assessment of how likely an event is to occur, expressed as a percentage. It's calculated using the formula:
Implied Probability = (1 / Decimal Odds) * 100%
For instance, if the odds for a team to win are 2.00, the implied probability is (1 / 2.00) * 100% = 50%. This means the bookmaker believes there's a 50% chance of that outcome happening.
Potential Payout and Profit
When you place a bet, you're interested in how much you stand to win. The calculator helps you determine:
- Potential Payout: This is the total amount you receive if your bet wins, including your initial stake.
Potential Payout = Stake Amount * Decimal Odds - Potential Profit: This is the net gain from your bet, excluding your initial stake.
Potential Profit = Potential Payout - Stake Amount
Bookmaker's Overround (Margin/Vigorish/Juice)
Bookmakers are in the business of making a profit, and they achieve this by building a margin into their odds. This margin is known as the "overround" (or vigorish/juice). In a perfectly fair market, the sum of the implied probabilities for all possible outcomes in an event would equal 100%. However, bookmakers adjust their odds so that this sum is always greater than 100%.
The overround is calculated by summing the implied probabilities of all outcomes in a market and then subtracting 100%.
Overround = (Sum of Implied Probabilities - 1) * 100%
For example, if a football match has three outcomes (Home Win, Draw, Away Win) with implied probabilities of 50%, 28.57%, and 25% respectively, the sum is 103.57%. The overround would be (1.0357 – 1) * 100% = 3.57%. This 3.57% represents the bookmaker's theoretical profit margin on that market.
A lower overround indicates a "tighter" market, meaning the odds are closer to the true probabilities and offer better value to the bettor. Conversely, a higher overround means the bookmaker is taking a larger cut.
Example Usage:
Consider a basketball game with the following decimal odds:
- Team A to Win: 1.80
- Team B to Win: 2.10
If you place a $50 stake:
- Team A (Odds 1.80):
- Implied Probability: (1 / 1.80) * 100% = 55.56%
- Potential Payout: $50 * 1.80 = $90.00
- Potential Profit: $90.00 – $50.00 = $40.00
- Team B (Odds 2.10):
- Implied Probability: (1 / 2.10) * 100% = 47.62%
- Potential Payout: $50 * 2.10 = $105.00
- Potential Profit: $105.00 – $50.00 = $55.00
- Market Overround:
- Total Implied Probability: 55.56% + 47.62% = 103.18%
- Overround: (1.0318 – 1) * 100% = 3.18%
This calculator empowers you to quickly analyze betting markets, understand the true cost of a bet, and identify potential value.