Bankroll Management Calculator
Find out how many buy-ins you need and what your risk of ruin is at your current bankroll.
Settings
Field size determines variance: larger fields concentrate prize money in fewer spots
Monthly EV
+10% × $10 × 20 tournaments
Risk of Ruin
Enter your bankroll to calculate
Recommended Bankroll
Buy-ins needed at each risk-of-ruin threshold
| Target | Buy-ins | Amount |
|---|---|---|
| 5% risk of ruin | 94 | $940 |
| 10% risk of ruin | 72 | $720 |
| 20% risk of ruin | 51 | $510 |
Risk of ruin uses the formula ROR = e^(−2 × ROI × N / σ²) where N is bankroll in buy-ins and σ is the standard deviation multiplier. Assumes normally distributed results per session.
What is risk of ruin?
Risk of ruin is the probability that your bankroll reaches zero before your edge plays out. Even a winning player can go broke if their bankroll is too small relative to the variance of the game. A 10% ROI with 2.5x standard deviation still has a 60%+ risk of ruin if you only have 10 buy-ins.
How does field size affect the calculation?
The field size buttons set a standard deviation multiplier: 2x for under 100 players, 2.5x for 100-500, and 3x for 500 and above. This multiplier appears squared in both the risk of ruin formula and the recommended buy-ins formula, so moving from a small field to a large field increases the required bankroll significantly even if your ROI stays the same.
The reason larger fields need a higher multiplier is their payout structure. Most of the prize pool is concentrated in the final table, so the vast majority of sessions end in a full buy-in loss and profit only materialises on infrequent deep runs. That produces wider result swings, which requires a larger bankroll buffer to survive long enough for your edge to play out. A player who beats small SNGs at 10% ROI and a player who beats large-field MTTs at 10% ROI need very different bankrolls because the underlying volatility per tournament is much higher in the latter case.
The field size thresholds are approximations, not exact boundaries. A 90-player turbo SNG and a 90-player deep-stack behave differently. Use the preset that best matches the payout structure of the tournament you play most, and err toward the higher multiplier if unsure.
How many buy-ins do I need for MTTs?
A common rule of thumb is 100 buy-ins for recreational grinders and 200 for anyone who relies on poker income. Larger-field tournaments with top-heavy prize pools increase variance significantly, requiring a bigger bankroll cushion. Select the 500+ players preset for these events.
What ROI is realistic?
In online MTTs, a 5-15% ROI is solid for a recreational winner. Regulars who study and play high volume tend to run 15-30%. Live MTTs often have softer fields but higher rake, so ROI expectations differ. Use your actual tracked results rather than estimates when possible.