Implied Probability in Sports Betting: How to Turn Odds Into Smart Bets

Implied probability is the percentage chance an outcome has according to the odds set by the sportsbook.

Example: +150 odds = 40% implied chance

• It tells you how likely the sportsbook believes an event is
• Every odds format (American, decimal, fractional) can be converted

Learning odds formats is crucial. Check out our money line bet calculator for instant conversions between American, decimal, and fractional odds.

Sportsbooks don't offer fair odds—they build in profit (aka "vig" or "overround").

Understanding implied probability lets you:

• See the true cost of a bet
• Spot mispriced lines
• Find +EV bets when your estimate beats the implied %
• Combine multiple legs with true value using our EV parlay builder

Want to understand expected value better? Our no vig calculator reveals the true odds by removing sportsbook juice.

Here's how to convert American odds to implied probability:

Positive odds (+150):
100 / (odds + 100) × 100 = implied %
→ 100 / (150 + 100) = 40%

Negative odds (-200):
odds / (odds + 100) × 100 = implied %
→ 200 / (200 + 100) = 66.67%

Too much math?
Use our implied odds calculator to calculate it instantly. Also explore our complete betting tools hub for all your calculation needs.

Let's say:

• Bookmaker gives +150 on a team → 40% implied chance
• You believe that team actually has a 50% chance

✅ That's a value bet (your estimate > their implied %)

This concept is the foundation of value betting and expected value (EV) strategies. Learn more with our guide on hedging bets to protect your value bets once you've placed them.

FanDuel gives Team A at +160 (38.5%)
BetOnline gives Team A at +140 (41.7%)

→ The FanDuel line is more profitable, but only if your true estimate is higher than 38.5%

This is why comparing sportsbook odds is critical. Use our parlay calculator to stack value bets smartly across different books.

Sportsbooks add a margin to ensure profit. This creates an overround—a total implied probability greater than 100%.

Example: Two teams both listed at -110
Implied probability each = 52.38%
Total = 104.76% → That 4.76% is the book's cut

Knowing this helps you avoid bad prices. Professional bettors use tools like our arbitrage calculator to exploit these margins across multiple sportsbooks.

Once you master implied probability, you can level up:

• Parlays: Combine multiple +EV bets using our ultimate parlay betting guide
• Hedging: Protect profits with our hedge calculator
• Arbitrage: Lock in guaranteed profits across multiple books
• Sports-Specific Strategies: Check our NFL betting strategies and NBA betting strategies

Implied probability is how sportsbooks speak in percentages. Once you understand that, you're no longer a blind bettor—you're calculating risk, spotting inefficiencies, and betting smart.

• Use our betting tools hub to convert odds and find value
• Check the EV parlay builder to go deeper
• Always compare odds before placing a bet
• Explore underdog betting strategies for contrarian value