Statistics calculators
Mean, median, variance, Pearson correlation, sample size, weighted average, and z-score from lists you type.
13 tools
In this group
Open average for mean, sum, and range. Median and mode resist outliers. Standard deviation and variance are the same engine with different wording. z-score standardizes one value. Paired lists are Pearson r. Educational Wald n is sample size. Weighted rows are weighted average.
- Bayes Theorem Calculator Update a prior with evidence. Enter P(A), P(B|A), and P(B) to get the posterior P(A|B) = P(B|A) P(A) / P(B).
- Binomial Probability Calculator Exact P(X = k), P(X ≤ k), and P(X ≥ k) for a binomial experiment with n trials, success probability p, and k successes. n is capped at 1000 on this page.
- Confidence Interval Calculator Build a normal (z) confidence interval for a mean from sample mean, SD, sample size, and a common confidence level. Educational large-n form, not a Student-t table product.
- Correlation Calculator Pearson product-moment r for paired numbers. Type one x y pair per line. r sits between -1 and 1. This is not Spearman rank or a p-value table.
- Average Calculator Arithmetic mean, sum, count, min, max, and range of a list you type.
- Median and Mode Median and mode of a numeric list. Ties for mode are listed together.
- Probability Calculator Combine two probabilities with and, or, not, or conditional rules. Toggle independence or type P(A and B) when events depend on each other.
- Sample Size Calculator Wald sample size for a proportion. n = z^2 p (1-p) / e^2. Optional finite N. Educational, not a survey product and not a power analysis for a mean.
- Standard Deviation Calculator Population and sample standard deviation and variance for a list you type.
- t-Score Calculator Compute the one-sample t statistic from a value x, hypothesized or sample mean, sample SD s, and sample size n. Educational arithmetic only; no critical-value table.
- Variance Calculator Population and sample variance, with matching standard deviations.
- Weighted Average Weighted average from value-weight pairs. Weights must sum to more than 0.
- Z-Score Calculator z = (x − mean) / SD. Standard deviation cannot be 0.