CodeASystem calculators

Statistics calculators

Statistics10

Statistics calculators for mean, median, mode, standard deviation, z-scores, confidence intervals and linear regression.

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10 tools

Paste any list of numbers to get the mean, median and mode at once, plus count, minimum, maximum and sum.

Compute sample or population standard deviation and variance from any list of numbers, with the mean shown alongside.

Calculate sample or population variance from a list of numbers, with the standard deviation and mean shown for context.

Convert a raw score into a z-score and see its percentile on the standard normal curve instantly.

Build a 90%, 95% or 99% confidence interval for a mean from your sample mean, standard deviation and size.

Find how many survey responses you need for a given margin of error, with a finite-population correction option.

Combine two event probabilities into P(A or B), handling mutually exclusive and independent events correctly.

Compute C(n,r) combinations and P(n,r) permutations together, with exact loop-product arithmetic for large n.

Fit the least-squares line y = mx + b to paired data and get slope, intercept and R² with the equation spelled out.

Compute Pearson’s r for paired data and get a plain-language strength and direction interpretation.