The Bankroll Manager calculates four key metrics every serious casino player should know: optimal bet size using the Kelly criterion, probability of going broke (risk of ruin), expected value per session, and how long your bankroll will last at your current stakes. It uses the exact same maths that professional sports bettors and poker players use to size their bets — adapted for casino games.

Set your bankroll, choose a game preset (blackjack, roulette, baccarat, slots, craps, or sports betting), then adjust bet size and session length. The tool will show your risk of ruin, expected loss, and Kelly-optimal bet size in real time. The risk of ruin metric tells you the probability you will lose your entire bankroll at the chosen bet size — aim for under 5% for sustainable play.

For UK casino players specifically: pair this with our monthly budget planner and dispute filing tool for a complete player protection workflow. The Kelly calculator assumes you have a real edge — against the house edge built into every casino game, Kelly returns 0, meaning the mathematically optimal bet is the smallest possible. Use this calculator to confirm that, not to chase losses.