# Guide to the betting calculators

The betting calculators do the arithmetic behind odds: the same odds written as decimal, American or fractional, the probability the odds imply, the payout for a stake, and the stake size the Kelly criterion gives for your own estimate of the win probability.

## Betting

### [Kelly Criterion Calculator](https://www.calculator.land/calculators/kelly-criterion/)

Calculates the Kelly criterion stake for a bet from the odds (decimal, American or fractional) and either your own estimate of the win probability or your edge in percent, scaled by a Kelly multiplier from 0 to 1.5. It shows the edge, the stake as a share of the bankroll and, with a bankroll entered, as an amount, along with the implied probability, expected value, growth per bet, a theoretical risk of ruin and the expected bankroll after a chosen number of bets. Two charts compare full, half and quarter Kelly and project the bankroll over 100 bets against not betting.

### [Odds Conversion Calculator](https://www.calculator.land/calculators/odds-converter/)

Converts odds between decimal, American and fractional formats and shows the implied probability the odds correspond to; you can also enter a probability in percent to get the odds. With a stake entered, it shows the total payout and the net profit if the bet wins, and each converted value can be copied with a click.