Value Bet Calculator

How the Value Bet Calculator Works

The only mathematically proven path to long-term profit in sports betting is consistently finding positive expected value (+EV) — situations where the true probability of an outcome is higher than what the bookmaker's odds imply. This calculator automates that process by stripping the vig from sharp market odds to find the true fair price, then comparing it to what your local bookmaker is offering.

Why Use Sharp Odds as the Benchmark?

Sportsbooks like Pinnacle and exchanges like Betfair operate with extremely thin margins and attract sharp money. Their lines are considered the closest thing to a true market price for sports outcomes. By using their odds for both sides of a market, we can calculate the no-vig probability — the true estimated chance of each outcome happening, with the bookmaker's profit margin removed.

Understanding the Three Key Numbers

• Expected Value (EV%): The most important number. A positive EV means that for every unit wagered, you expect to profit that percentage over a large sample. +5% EV means that betting $100 repeatedly at this price should return $105 on average per bet.
• Win Probability: The true estimated probability of the outcome, derived from the sharp market with the margin stripped out. This is what the market believes, not what the local bookmaker's odds imply.
• Kelly Stake: A mathematically optimal bet-sizing formula that maximizes long-run bankroll growth. The calculator uses a conservative quarter-Kelly (25% of full Kelly) to account for real-world variance. Enter your bankroll to see the recommended dollar amount.

The Edge Meter

The visual edge meter shows where your current EV sits on a scale from -15% to +15%. The marker turns red for negative EV and green for positive EV. A good value bet typically shows +3% or higher — anything below that is close to a coin flip with the house maintaining its margin. Anything above +8% is a significant edge and warrants serious attention.