Betting calculators
Free, no signup, and nothing is sent anywhere — the arithmetic runs in your browser.
Expected value calculator
Enter a price, what you think the real chance is, and your stake. Expected value is what a bet returns on average if you could make it many times — positive when your probability is higher than the price implies, and that gap is the only reason to take a bet.
Odds converter
Enter a price in any format and get the others, plus the probability it implies. American is standard in the United States, decimal across Europe and Australia, fractional in British racing — the same price written three ways.
Arbitrage calculator
Enter the best price available on each outcome and a total stake. The calculator splits the stake so that every outcome returns the same amount, and tells you whether that return beats what you put in.