Statistics
Descriptive statistics with dot plots and box plots
About this calculator
The Statistics Calculator computes descriptive statistics for any list of numbers — mean, median, mode, standard deviation, variance, quartiles, and more. Enter up to 100 values and instantly see a dot plot and box plot that make your data easy to understand. Useful for school, research, and everyday data analysis.
How to compute descriptive statistics
- Type your numbers into the data field, separated by commas.
- Read the headline statistics: mean, median, mode, min, max, range.
- Check spread with variance, standard deviation, and IQR.
- Inspect the dot plot and box plot to spot outliers and the overall distribution.
Common examples
- Data: 2, 4, 4, 4, 5, 5, 7, 9 → mean = 5, median = 4.5, mode = 4
- Data: 10, 20, 30, 40, 50 → mean = 30, range = 40, std dev ≈ 14.14
- Data: 1, 1, 2, 3, 5, 8, 13 → Q1 = 1, median = 3, Q3 = 8, IQR = 7
- Data: 100, 100, 100 → mean = 100, std dev = 0, mode = 100
- Data: 5, 10, 15, 100 → mean = 32.5, median = 12.5, 100 is a potential outlier
Frequently asked questions
What statistics does this calculator compute?
Count, sum, mean, median, mode, minimum, maximum, range, first and third quartiles, interquartile range, and both sample and population variance and standard deviation. It also flags potential outliers using the 1.5 × IQR fence.
What is the difference between sample and population standard deviation?
Population standard deviation treats the data as the entire group. Sample standard deviation treats it as a subset drawn from a larger population and divides by n − 1 (Bessel's correction). When n = 1, the sample version is undefined.
Which method does the calculator use for quartiles?
The median-of-halves method. Sort the values; if n is odd, exclude the overall median from both halves; if n is even, split evenly. Q1 and Q3 are the medians of those halves. The same method is used everywhere in the UI, the tests, and the visuals.
Can I enter very large datasets?
Version 1 caps the input at 100 values to keep shared URLs practical to send. Invalid or empty entries between commas are dropped during normalization and an inline warning notes how many were skipped.