# Statistics Calculators

- **URL:** https://codeasystem.com/calculators/statistics/
- **Markdown index:** https://codeasystem.com/calculators/statistics/index.md
- **Calculators in this category:** 10

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

Focus areas: Averages, spread, probability and regression.

## All calculators
- [Mean, Median & Mode Calculator](https://codeasystem.com/calculators/statistics/mean-median-mode-calculator.md); Paste any list of numbers to get the mean, median and mode at once, plus count, minimum, maximum and sum.
- [Standard Deviation Calculator](https://codeasystem.com/calculators/statistics/standard-deviation-calculator.md); Compute sample or population standard deviation and variance from any list of numbers, with the mean shown alongside.
- [Variance Calculator](https://codeasystem.com/calculators/statistics/variance-calculator.md); Calculate sample or population variance from a list of numbers, with the standard deviation and mean shown for context.
- [Z-Score Calculator](https://codeasystem.com/calculators/statistics/z-score-calculator.md); Convert a raw score into a z-score and see its percentile on the standard normal curve instantly.
- [Confidence Interval Calculator](https://codeasystem.com/calculators/statistics/confidence-interval-calculator.md); Build a 90%, 95% or 99% confidence interval for a mean from your sample mean, standard deviation and size.
- [Sample Size Calculator](https://codeasystem.com/calculators/statistics/sample-size-calculator.md); Find how many survey responses you need for a given margin of error, with a finite-population correction option.
- [Probability Calculator (P(A∪B))](https://codeasystem.com/calculators/statistics/probability-calculator.md); Combine two event probabilities into P(A or B), handling mutually exclusive and independent events correctly.
- [Combination & Permutation Calculator](https://codeasystem.com/calculators/statistics/combination-permutation-calculator.md); Compute C(n,r) combinations and P(n,r) permutations together, with exact loop-product arithmetic for large n.
- [Linear Regression Calculator](https://codeasystem.com/calculators/statistics/linear-regression-calculator.md); Fit the least-squares line y = mx + b to paired data and get slope, intercept and R² with the equation spelled out.
- [Correlation Coefficient Calculator](https://codeasystem.com/calculators/statistics/correlation-coefficient-calculator.md); Compute Pearson’s r for paired data and get a plain-language strength and direction interpretation.

Each link above points to the full Markdown reference for that calculator (inputs, formula, worked example, FAQs). The interactive HTML version lives at the same path without the `.md` suffix.

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Last updated: 2026-08-23 · [Section overview](https://codeasystem.com/calculators/index.md)