- Fraction Calculator
- Matrix Calculator
- Slope Calculator
- Algebra Calculator
- Trigonometry Calculator
- Percentage Calculator
- Probability Calculator
-
Probability X Greater Than a Value (Normal Distribution)Compute P(X > x) for a normal distribution from mean, standard deviation, and a value. Returns the right-tail probability, z-score, and percentage.
-
Parlay Odds CalculatorCalculate parlay payout and combined decimal odds for multi-leg bets. Enter your stake and up to 6 legs to see total payout and profit instantly.
-
Kelly Criterion CalculatorCalculate the optimal bet or investment fraction with the Kelly Criterion. Enter win probability and odds to get your ideal stake and half-Kelly amount.
-
Hypergeometric Probability CalculatorCompute hypergeometric probabilities P(X=k), cumulative P(X≤k) and P(X≥k), plus mean and variance for sampling without replacement.
-
Normal Probability Between Two X Values CalculatorFind P(a<X<b) for a normal distribution. Enter the mean, standard deviation and two X values to get the probability and z-scores instantly.
-
Probability of At Most k Successes (Binomial) CalculatorCompute the binomial cumulative probability P(X ≤ k) for n trials with success probability p. Free, instant, with mean and complement.
-
Probability of Exactly K Heads in N Flips CalculatorCompute the probability of getting exactly k heads in n coin flips using the binomial formula P = C(n,k) p^k (1-p)^(n-k). Free and instant.
-
Probability of At Least One Success in n TrialsCalculate the probability of at least one success in n independent trials using P = 1 − (1−p)^n. Free, instant complement-rule probability calculator.
-
Card Drawing Probability CalculatorCalculate the probability of drawing a given number of specific cards from a standard 52-card deck using the hypergeometric distribution.
-
Probability of Rolling at Least One SixCalculate the probability of rolling at least one six with n dice using P = 1 − (5/6)^n. Get the exact percentage and decimal odds instantly.
-
Binomial Probability CalculatorCalculate binomial probability P(X=k) for n trials with success probability p. Get exact, cumulative probabilities, mean, variance and standard deviation.
-
Normal Distribution Probability CalculatorCalculate normal distribution probabilities P(X<x) and P(X>x) from a value, mean and standard deviation using the standard normal CDF.
-
Normal CDF — Probability Less Than Z CalculatorCompute P(Z < z) = Φ(z), the standard normal cumulative probability below a z-score, plus upper tail and percentile. Optional μ and σ to standardize.
-
F1 Score CalculatorCalculate the F1 score, precision, and recall from True Positives, False Positives, and False Negatives. Free machine-learning classification metric tool.
-
Poker Hand Probability CalculatorCalculate the probability and odds of being dealt any 5-card poker hand from a standard 52-card deck, from royal flush to high card.
-
Monty Hall Problem Probability CalculatorCalculate the Monty Hall problem odds for any number of doors. See why switching wins (d−1)/d of the time and staying only 1/d.
-
Confidence Interval for a Proportion CalculatorCompute a confidence interval for a population proportion from successes and sample size at 90%, 95%, or 99% confidence using the normal (Wald) approximation.
-
One-Sample t-Test CalculatorCompute the one-sample t-test statistic from the sample mean, population mean, standard deviation, and size. Get t, degrees of freedom, and standard error.
-
Standard Error of the Mean (SEM) CalculatorCalculate the standard error of the mean (SEM) instantly from the sample standard deviation and sample size using SEM = s / √n.
-
One-Sample t-Test CalculatorCalculate the one-sample t-test statistic from sample mean, hypothesized mean, standard deviation and sample size. Get t, standard error and degrees of freedom.
-
Z-Score to Probability CalculatorConvert a z-score to a probability using the standard normal CDF. Get left-tail, right-tail, and two-tailed p-values from any z value instantly.
-
Probability CalculatorFree probability calculator for two independent events. Compute P(A and B), P(A or B), P(neither) and P(not both) instantly from decimal inputs.
-
Chi-Square Test Statistic CalculatorCalculate the chi-square (χ²) test statistic from observed and expected frequencies. Free goodness-of-fit calculator with degrees of freedom.
-
Weighted Mean CalculatorCalculate the weighted mean (weighted average) from a set of values and their weights. Enter comma-separated values and weights to get the result instantly.
