Statistics Calculators

Z-score, probability, variance, correlation, and more.

Z-Score Calculator
Enter a value, mean, and standard deviation to get the z-score and percentile.
Confidence Interval Calculator
Enter sample data and confidence level (90%, 95%, or 99%) to get the confidence interval and margin of error.
Probability Calculator
Enter favorable outcomes and total outcomes to calculate probability, percentage, and odds.
Combinations and Permutations Calculator
Enter n (total items) and r (items chosen) to get both combinations C(n,r) and permutations P(n,r).
Mean, Median, Mode Calculator
Paste a list of numbers to get mean, median, mode, range, min, max, and sum instantly.
Sample Size Calculator
Enter confidence level and margin of error to get the minimum sample size for a statistically valid study.
Variance Calculator
Enter a list of numbers to calculate variance and standard deviation for sample or population.
Correlation Coefficient Calculator
Enter two sets of paired numbers to calculate Pearson r, R², and interpret the correlation strength.
Percent Error Calculator
Enter experimental and theoretical values to calculate percent error, absolute error, and relative error.