Calculate profit and implied probability for "odds-on" favorites
Decimal (e.g. 1.50)
Fractional (e.g. 1/2)
American (e.g. -200)
"Odds on" means the value is less than 2.00 Decimal, or has a larger denominator in Fractional (1/2).
Total Payout$0.00
Net Profit$0.00
Implied Probability: 0%
Understanding "Odds On" Betting
In the world of sports betting and probability, "Odds On" refers to a price where the potential profit is less than the original stake. This typically happens when an outcome is considered highly likely to occur. For example, a heavy favorite in a tennis match or a top-tier football team playing at home often carries "odds on" prices.
How to Identify Odds On Prices
Decimal Odds: Any price below 2.00. (e.g., 1.50)
Fractional Odds: Any fraction where the denominator is larger than the numerator. (e.g., 1/2 or 4/9)
American Odds: Any negative number greater than -100. (e.g., -200 or -500)
The Mathematical Logic
When you place an odds-on bet, your Implied Probability is always greater than 50%. This signifies that the "house" or the market believes there is a high chance of success, requiring you to risk more capital to achieve a smaller gain.
Example: If you bet $100 on a team at 1/2 (Fractional) or 1.50 (Decimal):
Your Stake: $100
Your Profit: $50
Your Total Payout: $150
Implied Probability: 66.67%
Why Use This Calculator?
Professional bettors use an odds on calculator to quickly determine if the risk-to-reward ratio aligns with their "value" assessment. While the profit may be smaller, the frequency of winning is statistically higher. This tool ensures you know exactly what your return on investment (ROI) will be before committing your capital.
function toggleOddsHelp() {
var format = document.getElementById("oddsFormat").value;
var help = document.getElementById("oddsHelp");
var valInput = document.getElementById("oddsValue");
if (format === "decimal") {
help.innerText = '"Odds on" means the value is less than 2.00 (e.g. 1.25, 1.80).';
valInput.placeholder = "1.50";
} else if (format === "fractional") {
help.innerText = '"Odds on" means the right number is bigger (e.g. 1/4, 2/5).';
valInput.placeholder = "1/2″;
} else {
help.innerText = '"Odds on" are represented by negative numbers (e.g. -200, -450).';
valInput.placeholder = "-200";
}
}
function calculateOddsOn() {
var stake = parseFloat(document.getElementById("betStake").value);
var format = document.getElementById("oddsFormat").value;
var oddsRaw = document.getElementById("oddsValue").value.trim();
var profit = 0;
var payout = 0;
var prob = 0;
if (isNaN(stake) || stake <= 0 || oddsRaw === "") {
alert("Please enter a valid stake and odds value.");
return;
}
try {
if (format === "decimal") {
var dec = parseFloat(oddsRaw);
if (dec 0) {
// Odds Against
profit = stake * (am / 100);
prob = (100 / (am + 100)) * 100;
} else {
// Odds On
profit = stake / (Math.abs(am) / 100);
prob = (Math.abs(am) / (Math.abs(am) + 100)) * 100;
}
payout = stake + profit;
}
document.getElementById("resPayout").innerText = "$" + payout.toFixed(2);
document.getElementById("resProfit").innerText = "$" + profit.toFixed(2);
document.getElementById("resProb").innerText = prob.toFixed(2) + "%";
document.getElementById("oddsResults").style.display = "block";
} catch (e) {
alert("Calculation error. Please check your inputs.");
}
}