function updatePayout() {
var dec = parseFloat(document.getElementById("decimalOdds").value);
var stake = parseFloat(document.getElementById("stake").value);
var resultDiv = document.getElementById("payoutResult");
if (!isNaN(dec) && !isNaN(stake) && dec > 0) {
var total = dec * stake;
resultDiv.innerText = "Total Payout: " + total.toFixed(2);
} else {
resultDiv.innerText = "Total Payout: 0.00";
}
}
function calculateFromDecimal() {
var dec = parseFloat(document.getElementById("decimalOdds").value);
if (isNaN(dec) || dec = 2) {
amer = (dec – 1) * 100;
} else {
amer = -100 / (dec – 1);
}
document.getElementById("americanOdds").value = Math.round(amer);
// To Prob
var prob = (1 / dec) * 100;
document.getElementById("impliedProb").value = prob.toFixed(2);
// To Fractional
var numerator = (dec – 1) * 1000;
var denominator = 1000;
var gcd = function(a, b) { return b ? gcd(b, a % b) : a; };
var common = gcd(Math.round(numerator), denominator);
document.getElementById("fracNum").value = Math.round(numerator) / common;
document.getElementById("fracDen").value = denominator / common;
updatePayout();
}
function calculateFromAmerican() {
var amer = parseFloat(document.getElementById("americanOdds").value);
if (isNaN(amer) || amer === 0 || (amer > -100 && amer 0) {
dec = (amer / 100) + 1;
} else {
dec = (100 / Math.abs(amer)) + 1;
}
document.getElementById("decimalOdds").value = dec.toFixed(2);
calculateFromDecimal();
}
function calculateFromProb() {
var prob = parseFloat(document.getElementById("impliedProb").value);
if (isNaN(prob) || prob = 100) {
clearOthers("impliedProb");
return;
}
var dec = 100 / prob;
document.getElementById("decimalOdds").value = dec.toFixed(2);
calculateFromDecimal();
}
function calculateFromFractional() {
var num = parseFloat(document.getElementById("fracNum").value);
var den = parseFloat(document.getElementById("fracDen").value);
if (isNaN(num) || isNaN(den) || den === 0) {
return;
}
var dec = (num / den) + 1;
document.getElementById("decimalOdds").value = dec.toFixed(2);
calculateFromDecimal();
}
function clearOthers(source) {
var fields = ["decimalOdds", "americanOdds", "impliedProb", "fracNum", "fracDen"];
for (var i = 0; i < fields.length; i++) {
if (fields[i] !== source && !((source === "fracNum" || source === "fracDen") && (fields[i] === "fracNum" || fields[i] === "fracDen"))) {
document.getElementById(fields[i]).value = "";
}
}
}
function resetCalculator() {
document.getElementById("decimalOdds").value = "";
document.getElementById("americanOdds").value = "";
document.getElementById("impliedProb").value = "";
document.getElementById("fracNum").value = "";
document.getElementById("fracDen").value = "";
document.getElementById("stake").value = "100";
document.getElementById("payoutResult").innerText = "Total Payout: 0.00";
}
Understanding Betting Odds Formats
In the world of sports wagering and probability, "odds" are the measure of how likely an event is to occur. However, different regions across the globe use different numerical representations for these likelihoods. Our Odd Calculator simplifies this by converting between the four major formats instantly.
1. Decimal Odds (European)
Decimal odds represent the total payout for every 1 unit wagered, including the original stake. They are the most straightforward format for calculating potential returns.
Formula: Stake × Decimal Odd = Total Payout.
2. American Odds (Moneyline)
American odds are centered around a 100 base unit.
Positive Odds (+): Indicates how much profit you make on a 100 stake. A +200 odd means you win 200 on a 100 bet.
Negative Odds (-): Indicates how much you must stake to win 100 profit. A -150 odd means you must bet 150 to win 100.
3. Fractional Odds (British)
Popular in horse racing and the UK, these show the ratio of the profit won to the stake. For example, 5/1 (five-to-one) means you win 5 units for every 1 unit staked. If you see 1/2, it means you win 1 unit for every 2 units staked.
4. Implied Probability
This is the most critical metric for successful betting. It converts odds into a percentage, showing how often the bookmaker expects the event to happen. If the implied probability is lower than your own calculated probability, you have found "value."
Real-World Example Conversion
Let's look at an underdog with American Odds of +150:
Format
Value
Decimal
2.50
Fractional
3/2
Implied Probability
40%
A 100 stake on this outcome would result in a 250 total payout (150 profit + 100 original stake).