Odds Calculator

Convert between probability and odds in various formats

About Odds

Odds express the likelihood of an event as a ratio, commonly used in gambling, medicine, and statistics.

Formulas:

  • Odds: O = p / (1 - p)
  • Probability from odds: p = O / (O + 1)
  • Decimal odds: D = 1 / p

Examples:

  • 50% probability = 1:1 odds (even odds)
  • 25% probability = 1:3 odds (3 to 1 against)
  • 75% probability = 3:1 odds (3 to 1 for)