Poker Bankroll Calculator — Risk Management Tool

How to Use This Bankroll Calculator

1. Choose your game type. Select Cash Game or Tournament using the tabs above. Each format uses a different mathematical model because of how variance works in each format.
2. Enter your stakes and buy-in. For cash games, enter the stakes you play (e.g., 1/2 NL) and your typical buy-in in dollars. For tournaments, enter the buy-in amount.
3. Enter your win rate. Cash game players use bb/100 (big blinds won per 100 hands). Tournament players use ROI percentage (return on investment). A reliable estimate requires at least 50,000 hands or 500 tournaments of data.
4. Set your variance level. Low variance suits tight, full-ring games. Medium covers most 6-max cash games and standard MTTs. High is for aggressive styles, heads-up play, or turbo tournaments.
5. Choose your risk tolerance. 1% is the professional standard. 2% is reasonable for serious recreational players. 5% is aggressive and only recommended if you can easily reload.

Why Bankroll Management Matters

Even the best poker players in the world experience significant downswings. A winning player with a 5 bb/100 win rate at medium variance has roughly a 5% chance of experiencing a 40 buy-in downswing over any 100,000-hand stretch. Without an adequate bankroll, that downswing means going broke—regardless of skill level.

Bankroll management is the mathematical discipline of sizing your total poker funds so that the probability of going broke (your “risk of ruin”) stays below an acceptable threshold. The formula used for cash games is:

Bankroll = −ln(RoR) × SD² ÷ (2 × Win Rate)

Where RoR is your risk of ruin tolerance, SD is the standard deviation of your results, and Win Rate is your long-term expected win rate. All values are measured in big blinds per 100 hands.

Cash Games vs. Tournaments

Tournament players need proportionally larger bankrolls than cash game players because tournament variance is significantly higher. In a cash game, you can win or lose a few buy-ins per session. In a tournament, you will lose your buy-in the vast majority of the time, offset by occasional large scores. This “top-heavy” payout structure inflates variance dramatically.

Standard Deviation Explained

Standard deviation (SD) measures how much your results swing from session to session. A tight, value-oriented cash game player might have an SD of 60 bb/100, while an aggressive bluffer could see 100+ bb/100. Higher SD means larger swings and a bigger bankroll requirement for the same win rate.