Statistics

Statistics tools summarize lists, compute sample or population spread, and handle common planning formulas such as sample size and confidence intervals.

Sample versus population is a choice you make — the page does not guess which denominator you meant. Mean, median and mode answer different sentences about the same paste; a long tail can make the mean a poor “typical.”

Use the four-number page for school summaries, and the statistics calculator when you also need variance or both standard deviations.

Featured in this category

Statistics Calculator
Paste a list and get count, mean, median, mode, range, and both sample and population variance and SD.
Mean Median Mode Range
Paste a list of numbers to get the mean, median, mode and range in one place.
Standard Deviation
Paste a list of numbers and choose sample (n − 1) or population (n) standard deviation.

Guides

Mean, Median and Mode
The mean follows every value. The median is the middle after sorting. Mode is whatever appears most often. A long tail can make the mean a poor stand-in for “typical.”

Descriptive Statistics

Statistics Calculator
Paste a list and get count, mean, median, mode, range, and both sample and population variance and SD.
Mean Median Mode Range
Paste a list of numbers to get the mean, median, mode and range in one place.
Standard Deviation
Paste a list of numbers and choose sample (n − 1) or population (n) standard deviation.
Number Sequence
Find the nth term and the sum of an arithmetic or geometric sequence.

Probability

Probability Calculator
Combine two event probabilities as independent, mutually exclusive, or overlapping, plus complements and “at least one”.
Permutations & Combinations
Compute P(n, r) when order matters and C(n, r) when it does not, for whole numbers n ≥ r ≥ 0.

Statistical Inference

Z-score Calculator
Convert a value to a z-score, or a z-score back to the original scale, given a mean and standard deviation.
Confidence Interval
Build a z-interval for a mean from x̄, a standard deviation, n and a confidence level.
Sample Size
Estimate how many observations a proportion survey needs for a chosen confidence level and margin of error.

All statistics tools

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Standard Deviation
Paste a list of numbers and choose sample (n − 1) or population (n) standard deviation.
Number Sequence
Find the nth term and the sum of an arithmetic or geometric sequence.
Sample Size
Estimate how many observations a proportion survey needs for a chosen confidence level and margin of error.
Probability Calculator
Combine two event probabilities as independent, mutually exclusive, or overlapping, plus complements and “at least one”.
Statistics Calculator
Paste a list and get count, mean, median, mode, range, and both sample and population variance and SD.
Mean Median Mode Range
Paste a list of numbers to get the mean, median, mode and range in one place.
Permutations & Combinations
Compute P(n, r) when order matters and C(n, r) when it does not, for whole numbers n ≥ r ≥ 0.
Z-score Calculator
Convert a value to a z-score, or a z-score back to the original scale, given a mean and standard deviation.
Confidence Interval
Build a z-interval for a mean from x̄, a standard deviation, n and a confidence level.