Odds Calculator

Convert between odds and probability, calculate betting returns and odds ratios

Calculate Odds and Probability

Number of favorable outcomes

Number of unfavorable outcomes

Example Calculation

Football Team Example

Scenario: Your favorite team has odds 3:2 for winning

Chances for success: 3

Chances against success: 2

Total possible outcomes: 3 + 2 = 5

Calculation Results

Probability of winning = 3 ÷ 5 = 0.6 = 60%

Probability of losing = 2 ÷ 5 = 0.4 = 40%

Odds ratio = 0.6 ÷ 0.4 = 1.5

Decimal odds = 5 ÷ 3 = 1.67

Quick Reference

Odds to Probability

If odds are x : y in favor:

Probability = x ÷ (x + y)

Probability to Odds

If probability is p:

Odds = p ÷ (1 - p)

Odds Format Guide

Fractional Odds

3:2 or 3/2 (3 to 2)

Decimal Odds

1.67 (total return per unit)

American Odds

+150 or -200

Probability

60% or 0.6

Statistical Tips

Lower odds = higher probability of winning

Odds ratio > 1 means event is more likely than not

Break-even probability helps assess bet value

⚠️

Consider all factors beyond just odds

Understanding Odds and Probability

What are Odds?

Odds represent the ratio of favorable outcomes to unfavorable outcomes. They express the likelihood of an event occurring compared to it not occurring. Odds can be presented in different formats but convey the same statistical information.

Types of Odds

  • Odds for winning: First number is chances for success
  • Odds against winning: First number is chances against success
  • Decimal odds: Total return per unit bet
  • Fractional odds: Profit per unit bet

Key Formulas

Odds to Probability

P(win) = chances_for / (chances_for + chances_against)

P(lose) = chances_against / (chances_for + chances_against)

Probability to Odds

odds_ratio = P / (1 - P)

Decimal Odds

decimal_odds = 1 / probability

Practical Applications

Sports Betting

Evaluate betting opportunities and calculate potential returns

Risk Assessment

Quantify and compare different risk scenarios

Statistical Analysis

Convert between different probability representations