Calculate no vig from your inputs, with a result breakdown and worked steps.
No Vig Formula and Method
Raw implied fraction = 1 / odds
List every outcome of a single market, using decimal prices for selections that cannot win together and cover all possible results. Their reciprocal prices are raw implied fractions. The overround is their sum minus one, expressed in percentage points.
How to Use This Calculator
Select the result and any applicable method before entering the visible values. Check the selected record, unit and scoring conventions before calculating. Review the primary result and its breakdown, then open the calculation steps to see how the inputs were used.
Worked Example
With the example inputs in the table, the result is 4.712 percentage points. Proportional normalization makes the outcome probabilities add to 100%.
Normalized fraction = raw fraction / sum of all raw fractions
Input and Example Guide
| Input or category | Example or weight | Entry guidance |
|---|---|---|
| Every outcome price (decimal odds) | 1.91, 1.91 | Use matching entries separated by commas or spaces. |
| Outcome 1 normalized probability / fair odds | 50% / 2 | Calculated for the entered example. |
| Outcome 2 normalized probability / fair odds | 50% / 2 | Calculated for the entered example. |
Interpreting the Result
Proportional normalization divides each raw fraction by the total. This makes the adjusted fractions add to one and gives reciprocal normalized prices. It is one mathematical margin-removal convention. It does not correct favorite–longshot bias, account for missing markets or establish the true chance of a selection.
This removes margin proportionally. It is not a model of true probabilities or an adjustment for favorite–longshot bias; enter every mutually exclusive outcome.
Assumptions and Common Input Errors
Proportional normalization makes the outcome probabilities add to 100%. Keep the same currency and settlement conditions throughout a scenario. Displayed currency amounts are rounded to two decimals; calculations retain precision unless cent allocation is explicitly described.
Saving and Revising a Scenario
A successful calculation is saved in this browser and can be restored on the next visit. Editing an input clears the old result so it is not mistaken for an updated calculation. Reset returns the example inputs and clears the saved result.
Sources
Betfair Help, Decimal Odds and Stake-Inclusive Returns, reviewed 2026. Arithmetic and scenario assumptions are specified above.