Most bankroll calculators tell you your risk of going broke. This calculator answers the more practical question: “How much money do I actually need?”
By inverting the famous Risk of Ruin formula, this tool calculates the precise Bankroll ($B$) required to keep your risk ($r$) below a specific threshold (e.g., 1%), based on your Winrate and Variance.
Determine the Bankroll (B) needed for a specific Risk (r). Formula: B = (σ² * ln(1/r)) / (2μ).
How the Math Works
This tool solves for B (Bankroll) using the formula derived from Brownian motion:
- $\mu$ (Winrate): Your edge in bb/100.
- $\sigma$ (Std Dev): Your variance in bb/100.
- $r$ (Risk): Your maximum acceptable risk of ruin (e.g., 0.01 for 1%).
Example: Planning for Professional Play
You are a solid winner with a winrate of 4 bb/100 and a standard deviation of 100 bb/100. You want a professional safety net (1% Risk of Ruin).
- Calculation: The formula determines you need approx 5,757 Big Blinds.
- In Buy-ins: ~58 Buy-ins (at 100bb stack depth).
If you want to be safer (0.1% Risk), the requirement jumps to ~8,600 bb. This tool proves why “20 buy-ins” is rarely enough for serious grinding.
Frequently Asked Questions (FAQ)
Where do I find my Standard Deviation?
You can find this in your tracking software (PokerTracker 4 or Holdem Manager 3). Look for “Std Dev bb/100”. Typical values are 80-100 for NLHE and 120-160 for PLO.
Why does the required bankroll skyrocket for PLO?
Because variance ($\sigma^2$) is squared in the formula. If your deviation doubles (common in Pot Limit Omaha), your required bankroll quadruples to maintain the same safety level.