Free Odds Converter
Our free odds converter tool allows you to instantly convert betting odds between Decimal (European), American (US), and Fractional (UK) formats. Calculate the implied probability of any outcome and compare odds from different bookmakers. This calculator works in real-time without registration - simply enter your odds and get instant results.
Use the free calculator below to convert your odds instantly.
Odds Converter
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How It Works
The odds converter allows you to convert odds between three main formats used by bookmakers worldwide.
Odds Formats:
1. Decimal (European)
The most common format in Europe and Russia. Shows the total payout for 1 unit bet. For example, odds of 2.50 mean that for a bet of 100 units, you will receive 250 units (100 × 2.50), including your stake. Once you've converted your odds, use our parlay calculator to calculate combined odds for multiple selections.
2. American (US)
Used in the United States. Positive odds (e.g., +150) show how much you will win on a bet of 100 units. Negative odds (e.g., -200) show how much you need to bet to win 100 units.
3. Fractional (UK)
Traditional format in the United Kingdom. Shows net profit relative to the stake. For example, 3/2 means that for a bet of 2 units, you will win 3 units profit (plus get back your 2 units).
Implied Probability
Implied probability shows what probability the bookmaker has built into the odds. Calculated by the formula: Probability = 1 / Odds × 100%
For example, odds of 2.00 imply a 50% probability (1 / 2.00 × 100 = 50%). To find true probabilities without the bookmaker's margin, use our no-vig calculator.
Odds Converter Examples
Here are real-world examples of converting odds between different formats using actual betting scenarios from major sportsbooks.
Example 1: Converting Decimal to Other Formats
Example 2: Converting American to Decimal
Example 3: Converting Fractional to Decimal
How to Use the Odds Converter
Select Input Format
Choose the format of your odds: Decimal, American, or Fractional using the format buttons at the top of the calculator.
Enter Your Odds
Type in your odds in the selected format. For Decimal, enter a number like 2.50. For American, enter +150 or -200. For Fractional, enter numerator and denominator separately.
View Results Instantly
The calculator automatically converts your odds to all three formats and displays the implied probability. Results update in real-time as you type.
Compare and Analyze
Use the converted odds to compare offers from different bookmakers. Check the implied probability to understand the bookmaker's assessment of the outcome.
How the Odds Converter Works
The odds converter uses mathematical formulas to translate between different odds formats. Here's how each conversion works:
Decimal to American
If Decimal ≥ 2.00: American = (Decimal - 1) × 100
If Decimal < 2.00: American = -100 / (Decimal - 1)
Example: Decimal 2.50 → American +150 (since (2.50 - 1) × 100 = 150)
American to Decimal
If American > 0: Decimal = (American / 100) + 1
If American < 0: Decimal = (100 / |American|) + 1
Example: American -200 → Decimal 1.50 (since 100 / 200 + 1 = 1.50)
Fractional to Decimal
Decimal = (Numerator / Denominator) + 1
Example: Fractional 3/2 → Decimal 2.50 (since 3/2 + 1 = 2.50)
Implied Probability
Probability = (1 / Decimal Odds) × 100%
Example: Decimal 2.00 → Probability 50% (since 1 / 2.00 × 100 = 50%)
Frequently Asked Questions
An odds converter is a tool that translates betting odds between different formats (Decimal, American, Fractional) and calculates the implied probability of an outcome.
For Decimal odds ≥ 2.00, multiply (Decimal - 1) by 100 and add a plus sign. For Decimal < 2.00, divide 100 by (Decimal - 1) and add a minus sign. Our calculator does this automatically.
Yes, our odds converter supports all three major formats: Decimal (European), American (US), and Fractional (UK). You can convert between any of these formats instantly.
Implied probability is the percentage chance of an outcome as calculated from the odds. It shows what probability the bookmaker has built into the odds. Formula: (1 / Decimal Odds) × 100%.
Yes, our odds converter is completely free to use. No registration required, no hidden fees. Simply enter your odds and get instant conversions.