Poker Variance Calculator
Calculate expected profit ranges and confidence intervals based on your win rate, standard deviation, and sample size to understand your realistic outcomes.
Formula:Expected Value = (Win Rate / 100) × Hands
Your expected win rate in big blinds per 100 hands
Typical range: 60-120 BB/100 for cash games
Sample size for variance calculation
For converting results to currency (optional)
Try These Examples
Quick-start with common scenarios
Bankroll Simulator
Monte Carlo simulation with 1,000 iterations
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Your initial capital
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Your expected advantage
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Percentage of bankroll per bet
Total bets to simulate
How Poker Variance Works
Variance in poker measures how far your actual results can deviate from your expected results. Even with a positive win rate, short-term results are dominated by luck.
Standard Deviation (SD) quantifies your variance. With a win rate of $10/hr and SD of $80/hr, about 68% of your 100-hour samples will fall between$10 × 100 ± $80 × √100 = $1000 ± $800.
Sample size matters enormously. At 10,000 hands, a 5 BB/100 winner has about a 30% chance of being down money. At 100,000 hands, this drops to ~5%. Professional conclusions require 200,000+ hands.
Confidence intervals tell you the range where your results should fall:
- 68% of results fall within ±1 standard deviation
- 95% of results fall within ±2 standard deviations
- 99.7% of results fall within ±3 standard deviations
Frequently Asked Questions
What is variance in poker?
Variance measures how much your actual results deviate from expected results. Even if you're a winning player averaging $25/hour, you might have sessions losing $500 or winning $800 due to variance.
What is standard deviation in poker?
Standard deviation (SD) measures the spread of your results. A typical cash game player has SD of 70-90 BB/100. Higher SD means more swings. About 68% of your samples will fall within ±1 SD of your expected value.
How many hands do I need to beat variance?
You never fully 'beat' variance, but at 100,000+ hands your results become statistically significant. At 30,000 hands, confidence intervals are still very wide. Professional conclusions require 200,000+ hand samples.
Why are my results so different from my expected win rate?
That's variance in action. A player winning at 5 BB/100 might actually be down 20+ buyins after 50,000 hands and still be running normally. The confidence intervals show the realistic range of outcomes.
Does playing style affect variance?
Yes. Tight-aggressive styles have lower variance (SD ~70 BB/100). Loose-aggressive styles and players who bluff frequently have higher variance (SD ~100+ BB/100). Tournament players face extreme variance.
How this works
Calculations follow the published mathematics of the game — combinatorics for cards, probability theory for dice, and expected-value accounting for wagers. Results are verified against independent references (primarily Wizard of Odds). No calculation here is an opinion or recommendation; it is arithmetic applied to the rules of the game.
What this tool can’t do
When to consult a professional
This tool computes probability and expected value. It is not a betting system and cannot predict the outcome of any individual wager. If gambling is causing problems for you or someone you know, call the National Problem Gambling Helpline at 1-800-GAMBLER.
Sources
- [1]Wizard of Odds — Michael Shackleford, ASAIndustrywizardofodds.comAccessed Apr 21, 2026
Actuary; widely cited casino-game probability reference. Used for house-edge and EV verification.
- [2]National Council on Problem GamblingOfficial sourcencpgambling.orgAccessed Apr 21, 2026
Responsible-gambling guidance and 1-800-GAMBLER helpline.
Joseph OrdunaFounder & Software Engineer
Full-stack software engineer specializing in embedded systems, web architecture, and AI/ML. Founder of Practical Web Tools. Built the gesture-controlled drone IP acquired by KD Interactive (Aura Drone, sold on Amazon).