Gambling Math Calculators
Free educational tools to understand probability, expected value, risk analysis, and the mathematics that govern games of chance. Learn why the house always wins and make informed decisions.
New here? Start with Expected Value, then use Variance and Streaks to understand short-term swings. After that, move to Risk of Ruin and Bankroll Survival for long-term risk, and finally compare betting systems to see why progression strategies do not change underlying EV.
Probability Fundamentals
Master the core concepts that form the foundation of gambling mathematics. These tools answer: "Is this bet profitable on average?", "How volatile is it?", and "How likely are painful streaks?"
Expected Value Calculator
Calculate the average outcome of any bet. The foundation of all gambling math.
Variance Calculator
Measure how much outcomes deviate from expected value. Essential for understanding risk.
Probability of Streaks
Calculate winning and losing streak probabilities. Debunk the gambler's fallacy.
Guides for Probability Fundamentals
Read these first if you want formulas, interpretation tips, and common mistakes to avoid.
Advanced Risk Analysis
Explore tools for quantifying bankroll risk and understanding long-term outcomes. Use this group to estimate downside, time-to-ruin, and how quickly real results converge toward theoretical expectation.
Standard Deviation Calculator
Quantify outcome volatility. Understand the relationship between risk and reward.
Risk of Ruin Calculator
Calculate your probability of going broke before reaching your goal.
Law of Large Numbers Simulator
Watch how results converge to expected value over thousands of trials.
Bankroll Survival Time Simulator
Simulate how long your bankroll can survive against the house edge.
Guides for Advanced Risk Analysis
Use these guides to connect volatility, ruin probability, and bankroll lifespan in one workflow.
Betting Systems
Interactive simulators proving why no betting system can overcome the house edge. Experience each system firsthand and see the statistical proof of failure. Compare progression systems with flat betting and Kelly to separate bet sizing from edge.
Martingale Simulator
Double your bet after each loss. The most famous system that always fails.
Fibonacci Simulator
Gentler progression using the Fibonacci sequence. Still mathematically doomed.
Labouchere Simulator
Cancellation system with customizable sequences. Complex but equally futile.
Oscar's Grind Simulator
The most conservative system. Slower losses are still losses.
Flat Betting Calculator
The honest baseline. Same expected value as any system, without the drama.
Kelly Criterion Calculator
Optimal bet sizing for positive EV. The only math that actually works.
Guides for Betting Systems
Start here for the mathematical proof that systems do not beat negative EV, then learn when Kelly sizing is valid and when flat betting is safer.