1. Kelly Criterion Calculator

The Kelly Criterion is a mathematical formula used to determine the optimal size of a series of bets.

Bankroll Balance ($):

Odds (Decimal, e.g. 2.00):

Win Probability (%):

2. Martingale Risk Calculator

Calculate how much bankroll you need to sustain a losing streak when doubling your bet.

Base Bet ($):

Max Losing Streak (Spins):

Convert Decimal odds (European) to Fractional (UK) and Moneyline (US) formats instantly.

Decimal Odds (e.g. 1.50):