Descriptive Statistics calculators
Mean, spread, variation and data summaries.
One-Way ANOVA Calculator with ANOVA Table, Effect Size and Post-Hoc
Compare the means of three or more groups. Paste each group on its own line to get the full ANOVA table, F test, effect sizes and pairwise comparisons.
Average Deviation Calculator (Mean and Median) with Steps
Find the average deviation of a data set about its mean or its median, with the full deviation table and both versions side by side.
Chi-Square Calculator: Goodness of Fit and Test of Independence
Run a chi-square goodness-of-fit test or a test of independence on a contingency table. See expected counts, residuals, the p-value and an effect size.
Cochran’s Formula Calculator: Sample Size for Proportions and Means
Find the sample size you need with Cochran’s formula, for categorical or continuous data, then adjust for a finite population, design effect and non-response.
Coefficient of Variation Calculator (CV) from Data or Mean and SD
Compute the coefficient of variation from raw data or from a mean and standard deviation, and see what the result means in practice.
Confidence Interval Calculator for a Mean or Proportion (t, z, Wilson)
Calculate a confidence interval for a mean or a proportion. Choose the right method, see the margin of error and compare methods side by side.
Confusion Matrix Calculator: Accuracy, Precision, Recall, F1, MCC
Turn the four cells of a confusion matrix into every classification metric you need, with a heat-mapped matrix and confidence interval for accuracy.
Cosine Similarity Calculator for Two Vectors (with Angle and Distance)
Compare the direction of two vectors. Get cosine similarity, the angle between them and cosine distance, with the full dot-product working.
Curve Fitting Calculator: Linear, Polynomial, Exponential, Power, Logarithmic
Find the curve that best describes your data. Fit six model families at once, compare them fairly and get equations you can use for predictions.
Descriptive Statistics Calculator: Mean, Median, SD, Quartiles, Skewness
Paste a list of numbers to get every common summary statistic at once, plus a box plot, a histogram and an outlier check.
Shannon Entropy Calculator: Bits, Nats, Gini Impurity and Perplexity
Measure the uncertainty of a probability distribution in bits, nats or hartleys, with normalised entropy, Gini impurity and perplexity.
F1 Score Calculator: F-Measure from Precision and Recall or TP, FP, FN
Get the F1 score, the harmonic mean of precision and recall, plus F-beta variants that weight recall or precision more.
Histogram Maker and Calculator
Paste your data and get an instant histogram, a frequency table and the bin width, using an automatic bin count or your own.
Hypothesis Testing Calculator with Steps (z, t and Proportion Tests)
Work through a hypothesis test step by step. Enter your sample summary and get hypotheses, test statistic, p-value, critical value, interval and a conclusion in words.
Kurtosis Calculator: Excess Kurtosis, G2 and Normality Tests
Measure how heavy or light the tails of your data are. Shows excess kurtosis in all three common forms, a z-test and a Jarque-Bera normality check.
Level of Significance (Alpha) Calculator: Critical Values, Type I/II Error, Power
See what your chosen significance level α means: critical values, the rejection region, the Type I error rate and, optionally, the power and Type II error for a given effect size and sample size.
Mean Absolute Deviation (MAD) Calculator
Enter a list of numbers to find the mean absolute deviation, the average distance of the values from their mean, with every step shown.
Mean and Standard Deviation Calculator
Paste your data to get the mean, standard deviation, variance and standard error in one step, with the full working shown.
Mean, Median, Mode and Range Calculator
Enter a list of numbers to find the mean, median, mode and range in one go, with the working shown.
Mean Squared Error (MSE) Calculator with RMSE, MAE and MAPE
Score a forecast or regression model with MSE, then read RMSE, MAE, MAPE, bias and R² side by side so you know which metric to trust.
Nonlinear Regression Calculator: Exponential, Logistic, Michaelis-Menten, Gompertz
Fit curved models by true non-linear least squares with the Levenberg-Marquardt algorithm. Get parameters with standard errors, R² and a residual plot.
P-Value from Chi-Square Calculator (χ², df) with Critical Value Table
Convert a chi-square statistic and its degrees of freedom into an exact p-value, with the critical value, a shaded graph and a reference table.
Percentage Error Calculator: Percent Error Formula with Steps
Compare a measured value with the true value to get the percentage error, shown signed and absolute with the full working.
Raosoft-Style Sample Size Calculator (Margin of Error, Confidence, Population)
Work out how many survey responses you need, using the same inputs and formula as the Raosoft sample size calculator, plus a lookup table and a chart.
Regression Equation Calculator: Linear Regression Line, R², p-value and Prediction
Find the least squares regression line from your data. Get the equation, correlation, R², slope significance, a prediction with intervals and a residual plot.
RSD Calculator (Relative Standard Deviation)
Enter repeated measurements to find the relative standard deviation: the standard deviation expressed as a percentage of the mean.
Sample Variance Calculator (with Population Variance and Steps)
Calculate sample and population variance side by side, with the full squared-deviation table and a confidence interval for the true variance.
Sample Size Calculator: Estimate a Mean or Proportion, or Compare Two Groups
Plan your study size. Choose whether you are estimating a value or comparing two groups, and get the number of participants you need.
SEM Calculator: Standard Error of the Mean with Confidence Interval
Find the standard error of the mean from raw data or from summary statistics, with a confidence interval and a chart of how the SEM shrinks as n grows.
Skewness Calculator: g1, G1 and b1 with Significance Test
Measure how asymmetric your data are. All three common skewness formulas are shown, with a significance test and a plain-English reading.
SSE Calculator: Sum of Squared Errors, MSE, RMSE and R²
Compare actual and predicted values to get the sum of squared errors along with MSE, RMSE, MAE and R², plus charts that show where the error comes from.
Standard Deviation for Grouped Data Calculator (Frequency Table)
Enter a frequency table as class intervals and counts to get the mean, variance and standard deviation, with the complete working table.
Statistical Significance Calculator for A/B Tests (Two Proportions)
Check whether the difference between two conversion rates is statistically significant, with p-value, uplift, confidence interval and power.
T-Test Calculator: One-Sample, Two-Sample (Welch), Paired with Steps
Run a one-sample, paired or two-sample t-test from raw data or summary statistics. You get the t statistic, p-value, confidence interval, effect size and a ready-to-paste APA sentence.
Z Test Statistic Calculator: z-Score, Mean, Proportion, Two Proportions
Compute the z test statistic for a single value, a sample mean, a proportion or the difference of two proportions, with all the p-values you may need.
Z-Table Calculator: Z-Score to Probability and Back (Normal Distribution)
Look up standard normal probabilities without a printed table. Go from a z-score or a raw value to areas, or from a probability back to z.