Turn a complete set of market prices into margin-free probabilities and fair decimal odds using proportional normalization.
Changing an input marks the displayed result for recalculation.
Turn a complete set of market prices into margin-free probabilities and fair decimal odds using proportional normalization.
Calculations are informational. Actual grading, limits, deductions and payouts follow the operator’s rules.
At 1.91 and 1.91, the implied total is about 104.71%. Proportional normalization gives 50% per side and fair odds of 2.00.
This browser-based tool uses only the values entered on this page. It does not retrieve live odds, predict results or connect to a betting account.
Intermediate calculations retain full JavaScript precision; display values are rounded for readability.
Overround is meaningful only when the prices cover a complete set of mutually exclusive outcomes.
This calculator uses proportional normalization. Other models can produce different fair prices.
No. Convert them to decimal odds before using this calculator.
Each raw implied probability is divided by their total, so the normalized set sums to 100% apart from display rounding.
No. They are a mathematical repricing of the entered market, not a forecast of the event.
Confirm the odds format, stake basis, market scope and settlement rule before relying on the result.