- Fraction Calculator
- Matrix Calculator
- Slope Calculator
- Algebra Calculator
- Trigonometry Calculator
- Percentage Calculator
- Probability Calculator
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D10 Dice RollerRoll one or more ten-sided (D10) dice online and add a modifier. See each roll, the sum, and the grand total instantly with this free D10 roller.
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Combination without Repetition CalculatorCalculate combinations without repetition C(n,r) = n!/(r!(n-r)!). Find how many unique groups of r items can be chosen from n, order ignored.
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6-Sided Dice (D6) RollerRoll one or more virtual 6-sided dice (D6) with an optional modifier. See each roll, the total, min/max range, and expected average instantly.
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6-Sided Dice Probability CalculatorCalculate the probability of rolling any target sum with one or more standard 6-sided dice. Get favorable outcomes, percent chance, and odds.
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AND Probability CalculatorCalculate P(A and B), the probability that both events happen, for independent or dependent events. Enter P(A) and P(B) or P(B|A).
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99% Confidence Interval CalculatorCalculate a 99% confidence interval from your sample mean, standard deviation, and sample size using the z-score 2.576. Free and instant.
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95% Confidence Interval CalculatorCalculate a 95% confidence interval for a mean using x̄ ± 1.96 × (s/√n). Enter the sample mean, standard deviation, and size to get the margin of error.
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90% Confidence Interval CalculatorCalculate a 90% confidence interval from a sample mean, standard deviation, and sample size using the z-score 1.645. Get lower/upper bounds and margin of error.
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Normal Approximation to the Binomial CalculatorApproximate binomial probabilities with the normal distribution using continuity correction. Enter n, p, and x to get μ, σ, z-scores and P(X).
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Pearson Correlation Coefficient CalculatorCalculate the Pearson correlation coefficient (r) from paired X and Y data. Get r, r², and all sums instantly with this free statistics tool.
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Rayleigh Distribution CalculatorCompute the Rayleigh distribution PDF, CDF, mean, variance, median and mode for any value x and scale parameter sigma. Free and instant.
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Sampling Distribution of the Sample Proportion CalculatorFind the mean and standard error of the sampling distribution of the sample proportion using mean = p and SE = sqrt(p(1−p)/n). Free and instant.
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Relative Frequency CalculatorCalculate relative frequency by dividing a class frequency by the total count. Get the proportion and percentage instantly with a worked example.
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Empirical Rule CalculatorFree Empirical Rule (68-95-99.7) calculator. Enter the mean and standard deviation to find the ranges containing 68%, 95%, and 99.7% of normal data.
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Continuity Correction CalculatorApply the ±0.5 continuity correction to approximate a binomial with the normal distribution. Computes the corrected z-score from n, p, and x instantly.
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Beta Distribution CalculatorCompute the Beta distribution mean, variance, standard deviation, mode and probability density f(x) from shape parameters α and β. Free online tool.
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Chi-Square CalculatorCompute the chi-square (χ²) statistic from observed and expected values for a goodness-of-fit test. Get χ² and degrees of freedom instantly.
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Benford's Law CalculatorCalculate the Benford's Law probability for any leading digit 1-9 using P(d)=log10(1+1/d), plus the expected count within a sample size.
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Central Limit Theorem CalculatorApply the Central Limit Theorem to find the mean and standard error of the sampling distribution from population mean μ, standard deviation σ and sample size n.
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Elo Rating CalculatorCalculate your new Elo rating after a chess or game match. Enter ratings, result, and K-factor to find expected score and rating change instantly.
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Post-Test Probability CalculatorConvert pre-test probability and a likelihood ratio into post-test probability using Bayes' theorem and the odds form. Fast clinical decision tool.
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Roulette Payout CalculatorCalculate roulette payouts and odds for any bet. Enter your stake and numbers covered to see net profit, total return, and the true odds.
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Lottery Odds CalculatorCalculate your odds of winning any lottery. Enter total numbers, picks, and bonus ball pool to get exact jackpot probability using combinations C(n,k).
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Coin Toss Streak CalculatorCalculate the probability of getting a streak of k identical coin flips within n tosses, plus p^k and the expected number of runs. Works for biased coins.
