Betting Odds Calculator

Convert betting odds between formats and calculate potential payouts

Odds Information

Conversion Results

American Odds:
+100
Decimal Odds:
2.000
Fractional Odds:
1/1

Payout Information:

Potential Win:$100.00
Total Return:$200.00
Implied Probability:50.0%

Fair Value (No Margin):

American:-111
Decimal:1.900
Fractional:9/10

Understanding Betting Odds

American Odds

  • • Positive (+150): Profit on $100 stake
  • • Negative (-150): Stake needed for $100 profit
  • • Common in US markets
  • • Based on $100 unit

Decimal Odds

  • • Total return per unit wagered
  • • Includes original stake
  • • Popular in Europe
  • • Easy to calculate returns

Fractional Odds

  • • Profit relative to stake
  • • Traditional UK format
  • • Written as 5/1 (five-to-one)
  • • Historical horse racing format

Betting Concepts

Implied Probability

The probability of an outcome occurring based on the odds. Used to:

  • • Identify value bets
  • • Compare to actual probability
  • • Understand bookmaker margin
  • • Make informed decisions

Bookmaker Margin

The built-in profit margin in odds that ensures bookmaker profit:

  • • Also called "vigorish" or "juice"
  • • Affects true probability
  • • Varies by market/sport
  • • Higher in less competitive markets