Free tools

Calculators and utilities for people who think in odds, parlays, and head-to-head matchups. Free, no signup, no ads.

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Multiply odds across any number of legs. American, decimal, fractional. Combined odds, implied probability, payout, profit.

Convert American, decimal, and fractional odds to true implied probability — both directions.

Lock in profit on a live bet or parlay. Calculate the exact hedge stake.

Strip the book's margin. See the true probability behind a line.

Optimal bet sizing for your bankroll. Full and fractional Kelly.

Build a 4/8/16-team single-elimination bracket. Click winners to advance.