Odds Converter

Understanding Odds Formats

1

What are the different odds formats and how do they work?

American odds use + and - symbols (e.g., +150, -200), decimal odds show total payout (e.g., 2.50), and fractional odds show profit ratio (e.g., 3/2). American odds are standard in the US, decimal odds are used worldwide, and fractional odds are popular in the UK. Each format represents the same probability but displays it differently.

2

How do I convert American odds to decimal odds?

For positive American odds: Decimal = (American odds ÷ 100) + 1. For negative American odds: Decimal = (100 ÷ |American odds|) + 1. Example: +150 becomes (150 ÷ 100) + 1 = 2.50. -200 becomes (100 ÷ 200) + 1 = 1.50. Our calculator handles all conversions automatically.

3

What is implied probability and why is it important?

Implied probability is the percentage chance of winning implied by the odds. It includes the bookmaker's margin (vig). For example, +100 odds = 50% implied probability, +200 odds = 33.33%. Comparing implied probability to your assessment of true probability helps identify value bets. Only bet when your probability is greater than implied probability.

4

How do I calculate breakeven win percentage?

Breakeven percentage = 1 ÷ Decimal odds. For American odds: Positive = 100 ÷ (odds + 100), Negative = |odds| ÷ (|odds| + 100). Example: +150 odds = 100 ÷ 250 = 40% breakeven. You need to win 40% of the time to break even. Only bet when you expect to win more than the breakeven percentage.

5

Which odds format should I use?

Use American odds if betting in the US, decimal odds for international betting or calculations, and fractional odds for UK/Irish markets. Decimal odds are easiest for calculations and understanding payouts. American odds are intuitive for US bettors. Choose based on your location and preference, but understand all formats.

6

How do odds relate to probability and payouts?

Odds represent both probability and potential payout. Lower odds = higher probability = lower payout. Higher odds = lower probability = higher payout. For example, -200 odds mean 66.7% chance to win but only $50 profit on $100 bet. +300 odds mean 25% chance to win but $300 profit on $100 bet. Understanding this relationship is crucial for value betting.