Calculators
The arithmetic, in the open.
Eight free tools for the calculations behind a posted price. Every one shows its formula, states what it assumes, and refuses an input it cannot answer. No account, no signup, nothing saved.
- Odds converterConvert one price between American, decimal and fractional odds, and read the implied probability it carries.
- No vig calculatorRemove the book's margin from a two way or multi way market and read the fair probability of each outcome.
- Expected value calculatorEnter a price and your own win, loss and push probabilities to see the expected net return per unit staked.
- Parlay calculatorMultiply several legs into one combined price, gross payout and net profit, with the independence assumption stated.
- Kelly stake calculatorA hypothetical fractional Kelly figure from your own win probability estimate and a price, never a recommended stake.
- Hedge calculatorWork out the hedge stake that equalises an open position, and what the two outcomes are worth after it.
- Arbitrage calculatorCheck whether two complementary prices leave a theoretical arbitrage, and split a total stake between them.
- Bonus conversion calculatorCompare a non returned bonus stake with a cash stake, and convert a bonus into a fixed amount with a cash hedge.
Research only
These tools do arithmetic on numbers you type. They do not place bets, submit entries, estimate a probability for you, or tell you what to risk. Slateline is a research product. If gambling stops being fun, call 1-800-GAMBLER.