Single bet calculator
Enter the price and your own probability estimate.
Odds format
Sportsbook side
- Implied / break-even probability
- 52.38%
- Decimal / American
- 1.909 / -110
Your estimate
Enter a valid probability to see edge, fair odds and EV.
How this is calculated
- American +A → decimal 1 + A/100; −A → 1 + 100/A.
- Implied (break-even) probability = 1 / decimal odds (includes the book's margin).
- Edge = your probability − implied probability, in percentage points.
- Fair decimal odds = 1 / your probability.
- EV = p × profit_if_win − (1 − p) × stake. ROI = EV / stake.
Implied / break-even probability comes from the sportsbook's price. Your true probability is your own estimate, and the edge is only as good as that estimate. Results are uncertain, not guaranteed, and this is not betting advice.