Poker Variance Calculator

Calculate expected profit, confidence intervals, downswing risk, and bankroll requirements.

Your expected win rate in big blinds per 100 hands (bb/100). Typical good win rates: 2-10 bb/100 depending on stakes and game type.
bb/100
The standard deviation of your results in bb/100. Typical values: NL Hold'em cash ~75-100 bb/100, tournaments ~150-300 bb/100.
bb/100
How many hands you plan to play. Variance smooths out over larger samples. 100,000+ hands needed for statistically meaningful results.
$

Variance & Downswing Analysis

Expected Results

Expected Profit-
Standard Deviation over Sample-

95% Confidence Interval

Best Case (97.5th %ile)-
Worst Case (2.5th %ile)-

Downswing Risk

Probability of Being Down-
Expected Max Downswing-
Bankroll Needed (for 5% ruin risk)-
References: Variance = SD^2 * (hands/100). 95% CI = EV +/- 1.96*SD. Risk of ruin = e^(-2*WR*BR/SD^2). Based on random walk with drift model.