How to convert odds
Select the format of your odds, enter the price, then Calculate. An optional stake adds net profit and total return for a winning bet. Without a stake, conversions and probability still work. Pale example odds can be calculated immediately; focus the field to replace them. An empty field restores the example when you leave it.
Changing only the input format preserves the original odds. Editing a number clears the result until you calculate again. Copy result includes all formats, probability and stake calculations; Clear removes the inputs and result.
Conversion formulas
Let r be net profit per unit staked. Decimal odds D = 1 + r; fractional odds = r as a reduced fraction. For American odds A ≥ +100, r = A/100. For A ≤ −100, r = 100/|A|. Implied probability = 100/D percent.
Net profit = stake × r. Total return = stake × D and includes the original stake. A losing bet loses the stake; this tool does not model a series of bets.
Worked examples
Decimal 2.5 = American +150 = fractional 3/2, with 40% implied probability. A stake of 20 gives profit 30 and total return 50 if won.
American −150 = fractional 2/3 = decimal 1.666667 (rounded), with 60% implied probability. A stake of 30 gives profit 20 and return 50. +100 and −100 both mean decimal 2 and 50%.
Precision and scope
The entered odds are retained as an exact fraction while switching formats. Decimal and American displays round to 6 decimal places; probability to 4; monetary amounts to 2. Editing a rounded representation makes that new text the input. Decimal commas are accepted; grouping separators are not.
This is a single-price converter. It does not remove a bookmaker margin, calculate expected value or identify profitable bets. True probability may differ from implied probability. Fractional inputs describe profit, not total payout.
Frequently asked questions
Why does return include my stake?
Decimal odds multiply the entire winning return. Subtract the original stake to get net profit. The calculator labels both separately.
Can I enter American odds of +50 or −50?
No. Standard American odds use +100 or more, or −100 or less. Use decimal or fractional format for other representations.
Is a 60% implied probability a prediction?
No. It is the reciprocal of the decimal price. A bookmaker’s margin and market assumptions can make it differ from the actual chance.