Core steps
- Odds: Enter odds in one of the available formats.
- Result: Odds are converted to the other formats.
Odds Converter
An odds converter for American, decimal, fractional, and contract odds. Convert any price between formats and see the implied probability behind it.
You entered one set of odds.
DarkHorse Odds checks millions.
Converting between American odds and contract pricing is the easy part. Finding lines worth betting is not. The DarkHorse Odds Bet Finders identify the best bets across every book you use, updating as lines move.
- 69 sportsbooks searched
- Select your own odds format
- Contract prices converted for you
How to Use This Calculator
What Is An Odds Converter?
An odds converter takes odds in one format, such as American Odds, and converts it to another, such as contract pricing. The same bet can appear as -110, 1.9091, 10/11, 52.38%, or a contract price of 52.38¢. The format might be different but the payout is the same.
What Are American Odds?
The default format for US sportsbooks. They are tied back to $100.
- Positive numbers (+100, +200) show the profit a $100 bet returns. Example: a $100 wager on +250 has a profit of $250 and a total return of $350 including the original $100 bet amount.
- Negative numbers (-110, -200) show the amount that must be risked to win $100. Example: a $125 wager on a line that is -125 has a profit of $100 and a total return of $225, including the original bet amount.
What Are Decimal Odds?
The default in most of Europe and Australia. To determine the payout using Decimal odds just multiply the odds by the bet amount. Example: $75 bet on odds of 2.00, $75 × 2.00 is a total return of $150, for a profit of $75.
What Are Fractional Odds?
Common in the UK and Ireland. Written as a ratio (10/11, 5/2, 1/2) representing profit over stake. Example: a $20 bet on 5/2 means a $50 profit plus the $20 stake for a total return of $70.
What Is Implied Probability Pricing?
The percentage chance a price corresponds to, and the bridge between odds and expected value. To determine the payout, divide the bet amount by the implied probability. Example: a $10 bet at an implied probability of 25%. $10 ÷ 0.25 = $40. A total return of $40 on a $10 bet means $30 in profit.
What Are Contract Prices?
The format used by prediction markets including Kalshi, Polymarket, Novig, and ProphetX. A contract costs between 1¢ and 99¢ and pays exactly $1.00 if the outcome happens. To determine the payout, divide the bet amount by the contract price. Example: $60 at a contract price of 60¢ buys 100 contracts, for a total return of $100 resulting in a $40 profit.
The Conversion Formulas?
Most conversions are easiest in two hops: convert your odds into decimal first, then out of decimal into the format you want. Decimal is the natural middle step because it is a single number, with no plus or minus sign to track and no fraction to reduce. That means you only need the two short lists below instead of memorizing every pairing.
Converting into decimal
Converting out of decimal
Notice that the last two formulas are identical. Implied probability and contract price are the same number quoted two ways, as a percentage and as a price in cents. A 60% chance and a 60¢ contract are equal.
Example: Converting -150 American
A money line sits at -150 American.
Step 1. Convert the price to decimal
Step 2. Derive the fractional price
Step 3. Derive implied probability and contract price
All five figures describe one price. A bettor risking $150 to win $100 and a trader paying 60 cents for a dollar contract are taking the same position.
Odds Conversion Lookup Tables
Favorites: Negative American Odds
Underdogs: Positive American Odds
Why Odds Conversion Matters For Sports Bettors
Sportsbooks often default to American odds, decimal odds, or fractional odds based on your location. Prediction markets typically use contract pricing or implied probability. In order to compare who has the best price you need to be able to convert them.
Some odds formats also serve different uses for more advanced betting strategies. Decimal odds multiply cleanly, which is why they can easily be used to determine the payout for parlays. Implied probability is used to determine expected value. Contract prices are how prediction markets operate and settle contracts.
Conversion is also the first step in line shopping across venue types. A sportsbook quoting -150 and a prediction market quoting 60¢ are offering the same price. Without converting, the comparison cannot be made at all, and the better of the two prices goes unnoticed.
Common Mistakes
- Looking for American odds between -100 and +100. +50 or -75 are not valid American odds.
- Forgetting Fees. If you are using a prediction market, fees are typically not included in the listed price. Use the Prediction Market Fee Calculator to determine your true odds.
Frequently Asked Questions
What is an odds converter?
An odds converter translates a betting price between American, decimal, fractional, probability, and contract formats. Enter the odds in any one format and the calculator returns the equivalent in all the others.
How do I convert American odds to decimal?
For positive American odds, divide the odds by 100 and add 1. For negative American odds, divide 100 by the absolute value of the odds and add 1.
\[
\begin{aligned}
\text{Decimal (positive odds)} &= \dfrac{\strut \text{American}}{\strut 100} + 1 \\
\text{Decimal (negative odds)} &= \dfrac{\strut 100}{\strut |\text{American}|} + 1
\end{aligned}
\]
So +150 is 2.50 decimal, and -150 is 1.6667 decimal.
How do I convert decimal odds to American?
For decimal odds of 2.00 or higher, subtract 1 and multiply by 100. For decimal odds below 2.00, divide -100 by the decimal minus 1. So 2.50 decimal is +150 American.
How do I convert odds to probability?
Convert the price to decimal first, then divide 1 by that decimal. So 2.50 decimal is a 40.00% implied probability, and 1.6667 decimal is 60.00%. The result is the sportsbook's implied probability, which includes its margin.
\[
\text{Implied Probability} = \dfrac{\strut 1}{\strut \text{Decimal}}
\]
How do I convert probability back to odds?
Divide 1 by the probability to get decimal odds, then convert that decimal to whichever format you need. A 40% chance is 1 divided by 0.40, which is 2.50 decimal, or +150 American.
How do I convert fractional odds to decimal?
Divide the numerator by the denominator and add 1. So 3/2 becomes 1.5 plus 1, which is 2.50 decimal. Going the other way, subtract 1 from the decimal and reduce the result to a fraction.
How do I convert American odds to fractional?
Convert to decimal first, subtract 1, then reduce. So -150 becomes 1.6667 decimal, minus 1 is 0.6667, which reduces to 2/3.
What is a contract price in betting odds?
A contract price is 1 divided by the decimal odds: the cost in cents of a contract paying $1.00 if the outcome happens. A price of 60.00¢ means each contract costs 60 cents, and if the contract wins it settles at $1.00.
Why can I not enter odds between -100 and +100?
They are not a valid numbers for American odds. Even money is +100, and the next available American odds are -101 or +101.
How do I read fractional odds?
Read the numerator as profit and the denominator as stake. 7/2 means a $2 bet returns $7 in profit plus the $2 stake. 1/3 means a $3 bet returns $1 in profit plus the $3 stake.
Which odds format is the most accurate?
All of them represent the same underlying price. None is more accurate than another. They differ only in presentation, and in which calculations they make easier.
Does the implied probability shown include the vig?
Yes. The probability returned by this converter is calculated directly from the price, which has the sportsbook's margin built into it.
