Sports Betting Calculator
A free sports betting calculator for converting American, decimal, and fractional odds, calculating payouts, removing vig, and finding value bets. Enter any odds format and all other formats update instantly.
Odds Converter
Enter any odds format and the rest will auto-convert. Press Enter to copy focused value.
American to Implied Probability
Positive odds (+200): 100 / (odds + 100)
Example: 100 / (200 + 100) = 33.33%
Negative odds (-150): |odds| / (|odds| + 100)
Example: 150 / (150 + 100) = 60%
Decimal Odds
To probability: 1 / decimal
To American: If decimal ≥ 2: (decimal - 1) × 100
If decimal < 2: -100 / (decimal - 1)
No-Vig Calculation
The vig (juice) is the book's margin. To find fair odds:
1. Convert both sides to implied probability
2. Sum them (will be >100% due to vig)
3. Divide each by the sum to get true probabilityFair prob = implied prob / total prob
Expected Value (+EV)
A bet has positive expected value when your estimated probability exceeds the implied probability from the odds.Edge = Your prob - Implied prob
Positive edge = value bet worth considering.