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Statistics Calculator

Paste your data to see the mean, median, mode, range, quartiles, variance, standard deviation and other summary statistics together.

Formulas last reviewed: September 2026

Disclaimer: Results are calculated with standard formulas and are meant for learning and quick checks. Please double-check important work, especially anything used for exams, engineering, finance or safety.

A full summary of your data

The statistics calculator turns a list of numbers into a complete summary in one step. It reports the count and sum, the mean, median and mode, the range and quartiles, the variance and standard deviation, and other averages such as the geometric and harmonic mean.

Paste or type your data separated by commas, spaces or new lines. It handles up to 5,000 numbers and shows the sorted data too.

How it is calculated

Mean = sum ÷ count
Median = middle value of the sorted list
IQR = Q3 − Q1
Standard deviation = √(sum of squared deviations ÷ (n − 1))

Worked example

Data: 12, 15, 9, 21, 15, 18, 15, 30, 7, 24

Mean
16.6
Median
15
Mode
15
Range
23
Q1 · Q3
12 · 21
Sample SD
6.95

Which average should I use?

  • Mean uses every value but is pulled by extreme values.
  • Median is the middle value and ignores outliers, so it suits incomes and house prices.
  • Mode is the most frequent value and works for categories.
  • Geometric mean suits growth rates; harmonic mean suits rates such as speed.

Frequently asked questions

What are quartiles?

Quartiles split sorted data into four equal parts. Q1 is the 25th percentile, Q2 is the median and Q3 is the 75th percentile.

Why might the mode be none?

If every value appears only once there is no single most frequent value, so the calculator reports that there is no mode.

What is an outlier?

A value far from the rest. A common test flags values more than 1.5 times the IQR below Q1 or above Q3.

Which quartile method is used?

The median-of-halves method: the data is split at the median and the median of each half gives Q1 and Q3.