Sports Betting Calculators

Each calculator does one job, shows its formula and a worked example, and opens with real numbers already in it. The parlay settlement is the rule Agatha grades her own parlays by, and the CLV formula is the one her graded record uses.

Which one do you need?

• What does my parlay pay, and what if a leg pushes?Parlay calculator
• What is -135 as a decimal, and what win rate does it need?Odds converter
• What are the fair odds once the book's margin is removed?No-vig calculator
• How much should I bet on the other side to hedge?Hedge calculator
• How much of my bankroll does this bet deserve?Kelly calculator
• Did I get a better price than the close?CLV calculator

The calculators

• Parlay CalculatorPrice any parlay in any odds format, settle pushes and voids the way the books do, and see what the extra legs cost against fair odds.
• Odds ConverterTurn American, decimal, fractional or percentage odds into every other format, with the break-even win rate each price needs.
• No-Vig Fair Odds CalculatorRemove the book's margin from a two-way or three-way market to get fair odds, the vig and the hold, by three methods.
• Hedge CalculatorFind the hedge stake for an equal result or your stake back, see what each outcome nets, and see what the hedge itself costs.
• Kelly Criterion CalculatorSize a bet with full or fractional Kelly, and see how fast the answer changes when your win probability is a little too high.
• Closing Line Value CalculatorCompare the price you took with the closing price, with or without the vig, for one bet or a whole list at once.

Learn the math

The guides behind the calculators, each checked against Agatha's graded record.

• Sports Betting GlossaryShort definitions of the betting terms on this site, from odds formats and hold to Agatha's own words: lean, edge, seal and receipt.
• How Agatha Grades Every PickThe settlement rulebook behind Agatha's public record: wins, losses, pushes and voids, sport by sport, taken from the grader itself.
• What Is Closing Line Value (CLV)?Why the price you get says more than a winning week, how to measure it, and what Agatha's own picks show.
• Are Parlays Worth It? The Math of Stacking LegsHow each extra leg multiplies the book's margin, worked through with real prices and every parlay Agatha's graded picks could have made.
• How Long Do Losing Streaks Last?The math of losing runs and drawdowns at a given win rate, next to the longest streaks and the deepest drawdown in Agatha's own record.