Calculators
Enter your data and get instant statistical results
Mean Calculator
Enter a dataset and instantly calculate mean, median, mode, standard deviation, variance, range, and more. Perfect for students and analysts.
Regression Calculator
Input X and Y arrays to calculate slope, y-intercept, R², and Pearson's r. Includes an interactive scatter plot with the fitted regression line.
Statistical Tables
Reference critical values for hypothesis testing and confidence intervals
Z Table
Standard normal distribution table for z-scores from −3.5 to +3.5. Essential for hypothesis testing and confidence intervals.
Cumulative probabilities
4-decimal precision
T Table
Student's t-distribution critical values for degrees of freedom 1–30 and common significance levels (0.10, 0.05, 0.02, 0.01).
df 1 through ∞
Common alpha levels
Chi-Square Table
Chi-square (χ²) critical values for goodness-of-fit tests, tests of independence, and tests of homogeneity.
Right-tail probabilities
Usage examples
Glossary
Definitions for over 250 statistics terms
Statistics Glossary A–Z
A comprehensive dictionary of 250+ statistics terms and concepts. Each entry includes a short definition, a plain-language explanation, and contextual examples. Search by keyword or browse alphabetically.