Poker Variance Calculator (Free) — Expected Swing Range

Expected result2,500 bb ($5,000)

95% range-1,883 → 6,883 bb

95% range (USD)-$3,765 → $13,765

Probability of breakeven or worse7.8%

Over 50,000 hands at this win rate and SD, your result is very likely (95%) between -1,883 bb and 6,883 bb. Your sample is large enough that breakeven-or-worse is unlikely. Trust your win rate after samples this size.

What does poker variance look like in practice?

Variance is the statistical spread of your poker results around your expected win rate. Even a 5 BB/100 winner with normal SD has roughly a 15–25% chance of running break-even or worse over 50,000 hands. Tournament variance is much larger — a positive-ROI MTT player can easily go 200+ tournaments without a four-figure score. The calculator above turns these abstract truths into concrete swing ranges.

The math behind the calculator

For a sample of N hands with win rate WR BB/100 and standard deviation SD BB/100, the expected result is:

Expected = WR × N / 100

The standard error of that expected result is:

SE = SD × sqrt(N / 100)

And the 95% confidence interval is roughly:

Expected ± 1.96 × SE

This is why huge samples are required for win-rate certainty. SE shrinks with the square root of N, not linearly. To halve your confidence interval, you need 4× the hands. To shrink it to a quarter, 16×.

Three takeaways

A negative stretch is not a leak signal. Run the calc — if your downswing is within the 95% range, it is normal. Only outside-the-interval stretches warrant a real review of your play.
Short samples are not signal. 10,000 hands is too small to know your true win rate. 50,000 starts to be meaningful. 100,000+ is reliable.
PLO and mixed games are different animals. Doubling SD does not double your downswing risk — it quadruples the variance contribution. PLO bankroll requirements are higher for this reason, not because the game is "tougher."

Standard deviation reference

6-max NLHE cash: ~80–100 BB/100
Full-ring NLHE cash: ~70–95 BB/100
Live NLHE cash: roughly online range but with more table-condition noise
6-max PLO cash: ~130–170 BB/100
PLO5 cash: ~170–220 BB/100
Mixed games: dominated by the highest-variance component (typically PLO or stud)

Frequently asked questions

What is poker variance?

Poker variance is the statistical spread of your results around your expected win rate. A 5 BB/100 winner with high variance can lose for months and feel like a losing player. Variance is normal, expected, and the reason bankroll management matters. The calculator above shows the 95% range you should expect for a given sample.

How big can a normal poker downswing be?

For a 5 BB/100 NLHE cash winner with standard deviation 100, a 30 buy-in downswing over 50,000 hands is roughly a 1-in-20 occurrence — uncommon but absolutely normal. Tournament players face dramatically larger swings; 50+ buy-in tournament downswings are common over hundreds of events.

Is my downswing variance or am I playing badly?

Run the numbers. If your downswing is within the 95% confidence interval for your sample size and assumed win rate, it is statistically normal. If it sits outside the 95% interval, something has likely changed in your play, the games, or your mental state — investigate. Either way, the math tells you whether to be alarmed.

What standard deviation should I assume?

For NLHE cash: 80 BB/100 is tight, 100 is standard, 110+ is loose. For PLO: 130–170 is normal. For mixed games: typically the highest-variance component dominates. For online MTTs, variance is hand-irrelevant — what matters is buy-in standard deviation, which is roughly 100–150% of average buy-in over a multi-event sample.

How is this useful in practice?

Three uses: (1) understand whether your current downswing is "normal" or alarming, (2) set realistic expectations for what a positive win rate looks like over a finite sample, (3) build a bankroll that survives normal variance without breaking. All three reduce tilt and bad decisions.

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Last updated: May 19, 2026 · Written by Timothy J. Casatelli