Poker Bankroll Management Calculator
Determines how many buy-ins you need for your stakes given your win rate, variance, and risk tolerance. Essential for cash game and tournament players managing their poker funds responsibly.
About this calculator
Bankroll management balances your win rate against the natural variance of poker to keep your risk of ruin at an acceptable level. The core formula estimates the recommended buy-in count by dividing your current bankroll by a risk-adjusted unit that grows with volatility: recommended buy-ins = currentBankroll / (winRate × (1 + √(variance / 100) × ln(1 / riskOfRuin))). A higher standard deviation—common in tournaments or loose games—increases the denominator, demanding more buy-ins. Conversely, a strong win rate (BB/100) shrinks the required cushion. Risk of ruin is expressed as a decimal (e.g. 0.05 for 5%), and taking its natural log captures the exponential nature of ruin probability. Applying this formula prevents under-rolled play, the leading cause of preventable bankroll loss.
How to use
Suppose you have a $2,000 bankroll, win at 5 BB/100, have a standard deviation of 80 BB/100, and want no more than 5% risk of ruin (0.05). Step 1: compute the variance factor — √(80/100) × ln(1/0.05) = √0.8 × 2.996 ≈ 0.894 × 2.996 ≈ 2.678. Step 2: multiply by win rate — 5 × (1 + 2.678) = 5 × 3.678 = 18.39. Step 3: divide bankroll — $2,000 / 18.39 ≈ $108.75 per buy-in. You should play stakes where the maximum buy-in is around $100, e.g. $0.50/$1 NL.
Frequently asked questions
How many buy-ins do I need for cash games versus tournaments?
Cash game players typically need 20–30 buy-ins for recreational play and 50+ buy-ins for serious, low-risk grinders, because cash game variance is more predictable. Tournaments have much higher variance due to winner-takes-most payout structures, so professional tournament players often carry 100–200 buy-ins. The calculator accounts for this by weighting your standard deviation heavily — tournament players typically report standard deviations of 150 BB/100 or more. Always err on the side of more buy-ins when moving up stakes.
What win rate and standard deviation should I enter if I'm a new player?
If you have fewer than 50,000 hands, your observed win rate is not yet statistically reliable, so use a conservative estimate like 2–3 BB/100 rather than your tracked number. Standard deviation for a typical No-Limit Hold'em player ranges from 80–120 BB/100 for cash games and 150–200 BB/100 for multi-table tournaments. You can find your actual standard deviation in poker tracking software like PokerTracker or Hold'em Manager. Starting conservatively protects your bankroll while your sample size grows.
What is an acceptable risk of ruin percentage for a poker player?
Most professional and semi-professional players target a risk of ruin between 1% and 5%, meaning they are willing to accept a 1–5% chance of losing their entire bankroll before moving down stakes. Recreational players may tolerate 10–20% since they can reload from income. A 5% risk of ruin is a common baseline — it provides strong protection without requiring an excessively large bankroll. Lower targets (1% or below) dramatically increase the buy-ins required because the logarithmic relationship between ruin probability and bankroll size becomes very steep at low percentages.