De-vig a market to its fair odds.

De-vigging divides each outcome's raw implied probability (1 / decimal odds) by the sum of all implied probabilities, removing the bookmaker's margin to produce fair odds.

Fair odds are a reference, not a promise. The calculator divides each raw implied probability by their total, which assumes the margin is spread evenly across outcomes. Other methods make different assumptions, and none turns a market consensus into a prediction.

The overround is the book's margin. Two prices at 1.95 and 1.90 imply a total of about 103.9% — 3.9 points of built-in margin. The fair odds rebalance that total back to 100%.

A price set whose implied probabilities total below 100% has no built-in margin on paper. Before treating that as an edge, check fees, limits, and whether the prices are even available together.