Poker Bankroll Management Calculator
Estimates how many buy-ins your bankroll supports given your win rate, variance, and tolerated risk of ruin. Essential for cash-game grinders and tournament players sizing stakes responsibly to avoid going broke.
Last updated: May 2026
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About this calculator
Bankroll management balances your win rate against the natural variance of poker so that your probability of going broke (risk of ruin) stays at an acceptable level. The simplified formula used here is: recommended_unit = currentBankroll / (winRate × (1 + √(variance/100) × ln(1 / riskOfRuin))). Variables: currentBankroll (your total roll dedicated to poker, in dollars), winRate (in BB/100 — big blinds per 100 hands), variance (standard deviation in BB/100, typically 80–120 for NLHE cash, 150–200 for tournaments), riskOfRuin (decimal, e.g. 0.05 for 5%), gameFormat (preset buy-in multiplier, 20 BI for cash, 50 BI for SnG, 100 BI for MTT). A higher standard deviation widens the denominator, demanding more buy-ins; a strong win rate shrinks it. Taking the natural log of 1/riskOfRuin captures the exponential nature of bankroll-ruin probability — going from 10% to 1% risk requires far more than 10× the bankroll. Edge cases: a near-zero or negative win rate makes the formula degenerate (you cannot manage a losing strategy with bankroll alone); very high variance (200+ BB/100) compresses recommended stakes dramatically; the formula assumes a stationary win rate, which is rarely true as you move up stakes or change game types. The Chen formula, Kelly criterion, and Sklansky's 'risk of ruin' formula are alternative frameworks worth comparing.
How to use
Example 1: $2,000 bankroll, 5 BB/100 win rate, 80 BB/100 standard deviation, 5% risk of ruin. Step 1: variance factor = √(80/100) × ln(1/0.05) ≈ 0.894 × 2.996 ≈ 2.678. Step 2: denominator = winRate × (1 + 2.678) = 5 × 3.678 ≈ 18.39. Step 3: recommended unit = $2,000 / 18.39 ≈ $108.75. Play stakes where the buy-in is around $100 — for example, $0.50/$1 NL with a $100 max buy-in. Verify: this corresponds to ~20 buy-ins of $100, matching the cash-game rule of thumb. Example 2: $10,000 tournament bankroll, 30% ROI, 180 BB/100 variance, 1% risk of ruin. Step 1: variance factor = √(180/100) × ln(1/0.01) ≈ 1.342 × 4.605 ≈ 6.180. Step 2: denominator = 30 × (1 + 6.180) = 30 × 7.180 ≈ 215.4. Step 3: $10,000 / 215.4 ≈ $46.42. Restrict yourself to $44 buy-in MTTs, or about 200+ buy-ins — consistent with conservative tournament BRM doctrine.
Frequently asked questions
How many buy-ins do I need for cash games versus tournaments?
Cash players typically need 20–30 buy-ins for recreational play and 50+ buy-ins for full-time grinders, because cash game variance is moderate and outcomes converge faster. Tournaments have much higher variance due to winner-takes-most payout structures, so professional MTT players often carry 100–300 buy-ins. The calculator weights your standard deviation heavily — tournament players typically report 150 BB/100 or more, which automatically suggests larger bankrolls. Sit & Gos sit between these two extremes (50–100 BI). Always err on the side of more buy-ins when moving up stakes, since the player pool gets tougher at higher levels and your effective win rate usually drops.
What win rate and standard deviation should I enter if I am a new player?
With 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 NLHE player is 80–120 BB/100 for cash games and 150–200 BB/100 for MTTs. Tracking software like PokerTracker 4 or Hold'em Manager 3 reports both metrics automatically once you import a meaningful hand history. Starting with conservative inputs protects your bankroll while your sample size grows toward statistical significance. Update the inputs as your sample grows past 100,000 hands.
What is an acceptable risk of ruin percentage?
Most professionals target 1–5% risk of ruin — a 1–5% chance of busting their entire bankroll before moving down stakes. Recreational players who can reload from a day job may tolerate 10–20%, since the financial consequences of going broke are smaller. A 5% target is a common baseline: strong protection without requiring an absurdly large bankroll. Lower targets (1% or below) dramatically increase the required buy-ins because the logarithmic relationship makes bankroll demand steepen quickly. The right answer also depends on your psychology — many players cannot stomach the swings of 5%-risk staking and prefer 1% even at the cost of slower growth.
What are common mistakes when applying bankroll management math?
Using an inflated win rate from a hot streak (e.g., +10 BB/100 over 5,000 hands) instead of a regressed long-term estimate makes recommended stakes look much higher than is safe. Underestimating standard deviation — entering 60 when your true value is 100 — produces dangerous under-rolled recommendations. Ignoring rake at micro-stakes overstates your effective win rate by 4–8 BB/100. Treating tournament and cash bankrolls as fungible without re-running the calculation for each game type leads to over-confidence; the formulas weight variance differently. Forgetting to subtract life expenses (rent, food, taxes) from a dedicated bankroll leaves you bankroll-poor when bills arrive. Finally, the BB/100 metric assumes 100 hands per session unit — at full-ring live poker with 30 hands/hour, results take many more hours to converge.
When should I NOT use this bankroll management formula?
Recreational players whose poker stake is a small fraction of total wealth (under 5% of net worth) can ignore bankroll math entirely — they should focus on enjoyment and table selection. Professional players with a confirmed multi-year win rate may use Kelly criterion or Sklansky's exact risk-of-ruin formula instead, which give tighter bounds. Players running a backed or stake arrangement use entirely different math — their effective bankroll is the backer's, not their own. Live tournament players with a high proportion of $10k+ buy-ins typically use 50–100 BI bankrolls rather than this formula because the field is smaller and the variance is dominated by ICM-aware payouts. Negative-win-rate players cannot solve their bankroll problem with sizing — work on the game first. Finally, in jurisdictions where you cannot legally withdraw from your account quickly, treat the 'bankroll' as illiquid and demand a larger buffer.