Betting calculators

Work out arbitrage stakes across two, three or four outcomes. Shows the combined market percentage, the edge, and the return you are guaranteed on every result.

Split one total stake across several selections in the same market so each of them returns the same amount. Shows per-selection stakes and both outcomes.

Measure the margin built into a set of prices: the book percentage, the overround, the expected loss per unit staked, and de-vigged fair odds per outcome.

Convert decimal odds into implied probability, or a probability into the price that would be fair. Includes why a single price overstates the true chance.

Convert betting odds between decimal, fractional, American moneyline, Hong Kong and Malay formats, and see the implied probability of any price.

Work out the expected value of a bet from the price offered and your estimate of the true probability. Shows EV in money, EV%, fair odds and break-even probability.

Size a stake from your bankroll, the price offered and your estimate of the true probability. Shows full Kelly, fractional Kelly and the resulting stake.

Work out what an each-way bet actually costs and returns. Shows the derived place odds and the result if the selection wins, places, or does neither.

Calculate the exchange lay stake that equalises a back bet, with commission applied correctly. Shows liability, both outcomes, and the qualifying loss or free-bet retention.

Work out the lay stake, liability and retention percentage for a stake-not-returned free bet, with exchange commission applied to the lay winnings.

Work out the lay stake for a stake-returned free bet, with exchange commission applied. Shows liability, both outcomes and the retained value.

Work out the stake that closes an open back bet: lay it at an exchange, or back the opposing outcome at a bookmaker. Shows liability and both outcomes.

Compare a bookmaker cash-out offer against hedging the position yourself at an exchange, and see the margin built into the offer that the bookmaker does not show.