Prediction Market Calculators

Practical tools for analyzing implied probability, edge, and fair value. Select a calculator below to get started.

Bayes Update

Update a prior probability with new evidence using a likelihood ratio.

Find the minimum probability required to profit after fees.

Calculate your theoretical edge and expected value against the market price.

Convert between Probability, Decimal Odds, Moneyline, and Log Odds.

Convert a prediction market price into an implied probability percentage.

Determine the fair trading price for a given probability belief.