What are betting odds?

Betting odds represent the likelihood of an event occurring and determine how much money you can win from a bet. They serve two purposes: indicating the probability of an outcome and calculating potential payouts. Different regions use different odds formats—decimal odds are popular in Europe and Australia, fractional odds are traditional in the UK, and American odds (moneyline) are standard in the United States.

Understanding odds is essential for making informed betting decisions. The implied probability derived from odds shows you what the bookmaker believes is the chance of an outcome happening. Comparing implied probabilities across bookmakers helps identify value bets where the actual probability may differ from what the odds suggest.

Tool description

This odds calculator converts between all major odds formats instantly. Enter odds in any format—decimal, fractional, American, or probability—and see the equivalent values in all other formats. The calculator also computes implied probability and potential payout based on your stake amount.

Examples

Input Format Input Value Decimal Fractional American Implied Probability
Decimal 2.50 2.50 3/2 +150 40.00%
Fractional 5/1 6.00 5/1 +500 16.67%
American -150 1.67 2/3 -150 60.00%
Probability 25% 4.00 3/1 +300 25.00%

Features

  • Multi-format conversion: Instantly convert between decimal, fractional, American, and probability formats
  • Payout calculator: Calculate potential returns and profit based on any stake amount
  • Implied probability: See the true probability implied by any odds value
  • Real-time updates: Results update automatically as you type
  • Simplified fractions: Fractional odds are automatically reduced to their simplest form

How it works

All odds formats ultimately express the same information differently. The calculator uses decimal odds as the internal standard:

  • Decimal odds: Total return per unit staked (e.g., 2.50 means $2.50 return for every $1 bet)
  • Fractional odds: Profit relative to stake (e.g., 3/2 means $3 profit for every $2 staked)
  • American odds: Positive shows profit on $100 bet; negative shows stake needed to win $100
  • Probability: Percentage chance implied by the odds (calculated as 1 ÷ decimal odds × 100)

Options explained

Option Description
Odds Format Select the format of your input value (decimal, fractional, American, or probability)
Odds Value Enter the odds in your selected format
Stake Enter your bet amount to calculate potential payout and profit

Use cases

  • Comparing odds across bookmakers: Convert odds to a single format to easily compare prices from different betting sites that use different formats
  • Calculating bet value: Use implied probability to determine if odds offer good value compared to your own assessment of the outcome's likelihood
  • Quick payout estimation: Enter your stake to instantly see potential returns before placing a bet