Odds Converter
Convert between every odds format — and prediction-market prices — by editing any field.
Convert
Type into any row; the others update instantly.
e.g. +150 or −110
e.g. 2.50 (must be > 1)
e.g. 3/2
e.g. 40 (= 40¢ contract)
How to use this tool
- Type a value into whichever format you have.
- Every other format — including the prediction-market contract price — updates instantly.
- Use the implied probability to judge whether a price offers value versus your estimate.
The formula
decimal = 1 + (American/100 | 100/|American|) · implied % = 100 / decimal- Fractional is the continued-fraction reduction of (decimal − 1)
- Prediction-market ¢ = implied %
Worked example
+150 ⇒ 2.50 decimal ⇒ 3/2 ⇒ 40% implied ⇒ a 40¢ prediction-market contract. −110 ⇒ 10/11, not 909/1000.
Prediction markets: contract prices are quoted directly as probability in cents. Convert a Kalshi/Polymarket price to American or decimal here to compare it against a sportsbook line.