Decimal odds, implied probability and margin calculator

Use a worked calculation to understand a quote. The result is arithmetic, not a forecast or a recommendation to bet.

What the tool calculates

Implied probability before margin equals 100 divided by decimal odds. A potential winning return equals stake multiplied by decimal odds and includes the returned stake.

For a complete two-outcome market, the excess of the two inverse probabilities over 100% is the overround. Do not use the two-outcome calculation when a draw or another outcome is missing.

Try the numbers

The margin calculation assumes exactly two exhaustive outcomes. It is unsuitable if a draw or other outcome is missing.