Statistics Calculators
20 free calculators in this category. Every result is worked out in your browser — nothing you type is sent anywhere.
Binomial Probability Calculator
Find the probability of getting exactly, at most or more than k successes across n independent trials with a fixed success probability.
Open calculatorCombination (nCr) Calculator
Calculate the number of ways to choose r items from a group of n when the order of selection doesn't matter.
Open calculatorConfidence Interval Calculator
Calculate a confidence interval around a sample mean using the sample standard deviation, sample size and chosen confidence level.
Open calculatorCorrelation Coefficient Calculator
Measure the strength and direction of the linear relationship between two variables using up to 4 paired X and Y values.
Open calculatorExponential Smoothing Calculator
Forecast the next value in a chronological series of up to 8 data points using simple exponential smoothing with an adjustable smoothing factor.
Open calculatorGeometric Mean Calculator
Calculate the geometric mean of up to 8 positive growth factors, giving the equivalent constant compound growth rate.
Open calculatorInterquartile Range (IQR) Calculator
Calculate the interquartile range of up to 8 numbers and check for outliers using the standard 1.5×IQR fence rule.
Open calculatorLinear Regression Calculator
Fit a straight line through up to 4 paired X and Y values and predict Y for any given X using ordinary least squares.
Open calculatorMargin of Error Calculator
Calculate the margin of error for a survey result given the sample proportion, sample size and confidence level.
Open calculatorMoving Average Calculator
Smooth out short-term fluctuations in up to 8 chronological data points using a simple moving average over a chosen window.
Open calculatorNormal Distribution Calculator
Calculate the cumulative probability and density of a value under a normal (bell curve) distribution given its mean and standard deviation.
Open calculatorPercentile Calculator
Find the value at any percentile within a dataset of up to 8 numbers, using linear interpolation between sorted values.
Open calculatorPermutation (nPr) Calculator
Calculate the number of ways to arrange r items from a group of n when the order of selection matters.
Open calculatorProbability Calculator
Work out the probability of a single event from the number of favourable outcomes and the total possible outcomes.
Open calculatorQuartile Calculator
Split a dataset of up to 8 numbers into quarters and find Q1, the median (Q2) or Q3 using linear interpolation.
Open calculatorSample Size Calculator
Work out how many people or items you need to survey to reach a target confidence level and margin of error.
Open calculatorStandard Deviation Calculator
Work out the sample or population standard deviation of up to 8 numbers to see how spread out your data is around the mean.
Open calculatorVariance Calculator
Calculate the sample or population variance of up to 8 numbers, showing how far your data is spread from its average value.
Open calculatorWeighted Index Calculator
Combine up to 4 values with their own weights into a single weighted average or index number, similar to how a price index is built.
Open calculatorZ-Score Calculator
Find how many standard deviations a value sits above or below the mean, and its approximate percentile under a normal distribution.
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