Half-point value calculator
Web onlyEstimate the fair price after buying or selling half a point, with extra weight on key numbers.
−114
Buying half a point off −2.5 at −110 moves the win chance 0.9%: a fair −114.
- Base probability
- 52.38%
- Adjusted probability
- 53.28%
- Half-point impact
- 0.90%
Key numbers (3 and 7 in football) are worth more than other half points. Compare with the book's alternate lines.
How to use the half-point value calculator
Half-point value depends on how often games land on the number being crossed. Key football margins such as 3 and 7 usually carry more value than nearby numbers.
- 1Enter the current spread and price.
- 2Choose whether you are buying or selling a half point.
- 3Compare the estimated fair price with the sportsbook's offered adjustment.
Formula and assumptions
Adjusted win probability = original probability plus or minus the estimated push frequency crossed by the half point.
The model uses broad historical estimates and cannot capture every league, season, total, team, or market condition.
Questions
Answers about this free half-point value calculator, sports betting odds, payouts, and the math behind each result.
- Football scoring makes final margins of 3 and 7 more common than many nearby margins.
- No. It is useful only when the value of the crossed number is greater than the extra price charged.