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Odds Conversion Calculator | Universal Betting Tool

Convert between American, Decimal, and Fractional betting odds instantly while calculating implied probability and potential payouts.

Enter Your Odds

Choose the format your sportsbook or source uses

Enter odds in your selected format

$
USD

Optional: Enter wager to see payout

Implied Probability

50.00%

Win likelihood based on odds

Total Payout $200.00
Stake Included
Net Profit $100.00
Pure Winnings

Converted Odds Formats

Click value to copy
Decimal Multipler format (EU/AU/CA)
2.00
American Moneyline format (US)
+100
Fractional Ratio format (UK/IE)
1/1

1 Understanding Implied Probability

Implied probability is the single most important concept separating casual bettors from sharp bettors. It represents the sportsbook's assessment of the likelihood of an outcome, baked directly into the odds.

When you see odds of -110 (American) or 1.91 (Decimal), the sportsbook is implying a specific percentage chance that the event will happen. If your personal estimate of the true probability is higher than the implied probability, you have identified a value bet.

Note on Vig: Sportsbook odds rarely sum to exactly 100%. The excess percentage (often 104-105%) is known as the "vig" or "juice"—the house edge. For example, standard -110 odds on both sides of a spread imply a 52.38% probability for each, totaling ~104.8%.

2 The Three Odds Formats Explained

Format Region How it Works
American USA Positive (+): Profit on a $100 bet (e.g., +200 = win $200).
Negative (-): Amount to bet to win $100 (e.g., -150 = bet $150 to win $100).
Decimal Europe, Canada, Australia Multiply your stake by this number to get the Total Payout (Stake + Profit).
Fractional UK, Ireland Represents Profit per Unit Stake. 5/2 means $5 profit for every $2 wagered.

Why Convert Odds?

  • Compare Lines: Sportsbooks often display different formats. Converting them to a common language (like Decimal) allows for instant price comparison.
  • Find Value: It is easier to compare your own probability estimate (e.g., "I think they have a 60% chance") against Implied Probability % than against -150 odds.
  • Bankroll Management: Proper staking methods like the Kelly Criterion require decimal odds or probability inputs.

Payout vs. Profit: Know the Difference

One of the most common mistakes for new bettors is confusing "Payout" with "Profit".

  • Payout (Return): The total money the sportsbook sends to your account if you win. This includes your original bet money being returned.
  • Profit (Net Win): The actual money you made. Calculation: Payout - Original Stake.

Example: $100 Bet at 2.00 (Decimal) Odds

Payout: $200
Profit: $100

Finding Value: True Odds vs. Implied Odds

Profitable betting isn't about picking winners; it's about picking prices that are wrong. This is the concept of Value.

Step 1: Your Estimate

You analyze a game and determine Team A has a 55% chance of winning. This is your "True Probability."

Step 2: The Sportsbook

The book offers +100 (2.00) odds. This implies a 50% probability.

Since your True Probability (55%) > Implied Probability (50%), this is a Value Bet.

Frequently Asked Questions

Why don't the odds on both sides sum to 100%?
The difference is the sportsbook's "vig" or "juice"—their built-in profit margin. For example, -110 on both sides implies ~52.38% on each, totaling ~104.76%. The extra ~4.76% is the book's edge.
Can I use this calculator for live/in-play betting?
Absolutely. Odds change constantly during live events. The calculator instantly converts any odds entered, allowing you to make informed decisions in real-time.
How do I find arbitrage opportunities?
Compare odds on the same event across multiple sportsbooks. Convert all to Decimal format. If the sum of (1 / odds) for all possible outcomes is less than 1, an arbitrage opportunity exists.
Is there a best odds format?
Mathematically, Decimal is the simplest and most versatile for calculations. However, use whatever format you are most comfortable reading quickly.

Bet Responsibly

Betting should be treated as entertainment, not a source of income.

  • Set and stick to a betting budget (bankroll).
  • Only bet what you can afford to lose.
  • Avoid chasing losses.

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