Odds to Probability Converter
Instantly convert between Polymarket prices, American odds, and Decimal odds to find value in any market.
Used by Polymarket & Kalshi (e.g., 60¢ = 60%)
US Sportsbooks (e.g., -150, +200)
European/Global standard (e.g., 2.50)
UK/Irish standard (e.g., 5/2)
Quick Reference Guide
| Probability (Polymarket) | Decimal | American | Fractional |
|---|---|---|---|
| 10% (10¢) | 10.00 | +900 | 9/1 |
| 25% (25¢) | 4.00 | +300 | 3/1 |
| 50% (50¢) | 2.00 | +100 / -100 | 1/1 (Evens) |
| 75% (75¢) | 1.33 | -300 | 1/3 |
| 90% (90¢) | 1.11 | -900 | 1/9 |
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Understanding Betting Odds Formats
Implied Probability (Prediction Markets)
Prediction markets like Polymarket and Kalshi simplify betting by using percentages or "cents on the dollar" directly. A price of 60¢ means the market implies a 60% chance of that event happening. This is the most intuitive format for binary events ("Yes" vs "No").
Decimal Odds
Common in Europe and Australia. Represents the total return (stake + profit) for every $1 bet.
Odds = 100 / Probability
American Odds
Common in the US.
Positive (+200): Profit on a $100 bet.
Negative (-150): Amount to bet to win $100.
Fractional Odds
Common in UK/Ireland. Represents Profit / Stake.
A 3/1 bet means you win $3 profit for every $1 staked.