Convert betting odds instantly between American, Decimal, and Fractional formats
Example: +150, -200, +300
Example: 2.50, 1.80, 3.00
Example: 3/2, 5/1, 1/2
Converting betting odds between different formats is simple with our free calculator. Just enter the odds you have in any format, and the converter instantly translates them into the other two formats while calculating the implied probability.
This tool is essential when comparing odds across different sportsbooks or betting in different regions. European sportsbooks use decimal odds, UK bookies prefer fractional, and American sites display moneyline (American) odds.
Used in the US, shown with + or - signs. Positive odds (+150) show profit on $100 bet. Negative odds (-200) show how much to bet to win $100.
Popular in Europe and Canada. Shows total return per $1 wagered, including your stake. Odds of 2.50 mean you get $2.50 back for every $1 bet.
Traditional UK format. The fraction shows profit relative to stake. Odds of 3/2 mean you win $3 for every $2 wagered, plus your stake back.
American odds (also called moneyline odds) use positive and negative numbers. Here's how they work:
Positive odds (+150): You win $150 profit on a $100 bet. A $50 bet would win $75.
Negative odds (-200): You need to bet $200 to win $100 profit. A $100 bet would win $50.
Decimal odds are the easiest format for calculating payouts. Simply multiply your stake by the decimal number to get your total return (including your stake). Decimal odds of 3.00 on a $100 bet returns $300 total ($200 profit + $100 stake).
Fractional odds show potential profit as a fraction of your stake. Odds of 5/1 (read as "five to one") mean you win $5 for every $1 staked. A $100 bet at 5/1 would return $600 total ($500 profit + $100 stake back).
| American | Decimal | Fractional | Implied Probability |
|---|---|---|---|
| +100 | 2.00 | 1/1 (Evens) | 50.00% |
| +150 | 2.50 | 3/2 | 40.00% |
| +200 | 3.00 | 2/1 | 33.33% |
| +300 | 4.00 | 3/1 | 25.00% |
| -110 | 1.91 | 10/11 | 52.38% |
| -150 | 1.67 | 2/3 | 60.00% |
| -200 | 1.50 | 1/2 | 66.67% |
| -300 | 1.33 | 1/3 | 75.00% |
Implied probability converts betting odds into a percentage that represents the bookmaker's assessment of an outcome's likelihood. Understanding implied probability is crucial for finding value bets.
The key to profitable betting is finding situations where your calculated probability of an outcome is higher than the bookmaker's implied probability. This edge is how sharp bettors make consistent profits.
From Decimal Odds: Probability = (1 / Decimal Odds) × 100
From American Odds (Positive): Probability = 100 / (Odds + 100) × 100
From American Odds (Negative): Probability = -Odds / (-Odds + 100) × 100
Professional bettors use odds converters for several important reasons:
1. Comparing Lines Across Sportsbooks: Different betting sites may use different odds formats. Converting them all to one format makes it easy to find the best value.
2. Calculating Parlays: Decimal odds make parlay calculations much simpler. Convert your American odds to decimal before building multi-leg bets.
3. International Betting: If you're betting on European soccer using a UK site while primarily betting NFL on US sites, you'll need to quickly convert between formats.
4. Understanding True Probability: Converting odds to implied probability helps you assess whether a bet offers value based on your own analysis.
5. Betting Strategy: Many betting systems and strategies require calculations that work best in decimal format, regardless of how the odds are displayed.
Baseball moneylines are always in American format. If the Yankees are -150 favorites against the Red Sox at +130, our converter shows:
Most NFL spreads are -110 on both sides. Understanding this means:
Player props often have different odds. If LeBron over 25.5 points is -120 and under is -110:
European soccer sites typically show decimal odds. If you see Chelsea at 1.75, Man United at 4.50, and the draw at 3.60:
Line Shopping: Use this converter when comparing odds across multiple sportsbooks. A line of +150 at one book versus +145 at another may not seem like much, but over hundreds of bets, it significantly impacts your profitability.
Identify the Vig: Convert both sides of a bet to implied probability and add them together. If they total more than 100%, the difference is the bookmaker's edge (vigorish). Lower vig means better value for you.
Track Your CLV: Closing Line Value is crucial. If you bet a team at +140 and the line closes at +120, you got value. Our converter helps you quickly calculate if you beat the closing number.
Bankroll Management: Use the Kelly Criterion calculator alongside this odds converter to determine optimal bet sizing based on your edge and the odds offered.
Build Better Parlays: Convert all your legs to decimal odds before calculating parlay payouts. It's much faster than trying to work with American odds across multiple legs.
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See Our Verified Record 🎯Professional sports bettors maintain accounts at 5-10 different sportsbooks for one critical reason: line shopping. Getting -105 instead of -110 on the same bet might seem trivial, but over hundreds of bets, this 5-cent difference represents thousands in additional profit. The challenge? Each sportsbook displays odds differently. DraftKings uses American odds (-110), European books show decimal (1.91), and some UK sites default to fractional (10/11). Without instant conversion, comparing value across books becomes tedious and error-prone.
Here's a real NFL Sunday scenario: The Bills are favored against the Dolphins. FanDuel shows Bills -6.5 (-110). BetMGM displays -6.5 (1.909 decimal). Caesars lists -6.5 (-105). Converting these instantly reveals BetMGM at 1.909 decimal equals -110 American, while Caesars at -105 offers better value. On a $100 bet, you'd win $95.24 at -105 versus $90.91 at -110—a $4.33 difference. Repeat this across 200 NFL bets per season and you've gained an extra $866 just from optimal line shopping. Sharp bettors never place a bet without checking at least 3-4 books, and this converter makes that process instant.
The implied probability feature reveals even more. If multiple books show the Bills at 52-53% implied probability but one outlier shows 50%, you've found a soft line. Maybe that book's algorithm weighted an injury differently, or their betting public skewed the line. Converting every odd to implied probability lets you spot these discrepancies within seconds. Professional bettors use odds converters dozens of times daily, treating them like stock traders treat real-time price feeds. The edge isn't in picking winners—it's in consistently getting the best available number on your picks. This converter is the essential first step in that process.