How to use it
- Type or paste numbers separated by commas, spaces or new lines; a column copied from a spreadsheet works. Negative numbers, decimals and forms like 2.5e3 are accepted.
- Read the mean, median, mode, range, sum, count and both standard deviations.
- For a weighted average, switch modes and enter the values and their weights in the same order.
How it calculates
Every number is read as an exact decimal fraction rather than a floating-point value, so the sum, mean, median, range and variance are exact; the mean of 1, 2 and 2 is 5/3, shown as 1.666666666667… with the dots marking a rounded result. Values written differently but equal, such as 51 and 5.1e1, count as the same value for the mode. The median is the middle value after sorting, or the mean of the two middle values. The standard deviations are the square roots of the exact variances, dividing by n for the population version and n − 1 for the sample version.
What we tested
On October 14, 2026 we compared the page’s own functions with Python’s exact fractions and its statistics module on 3,502 random lists of integers, decimals, negatives, exponent forms and repeated values, plus weighted lists: every mean, median, mode, sum, range and weighted average matched to 12 decimal places and every standard deviation to 12 significant figures. The first run found one list where equal values written two ways (as in 51 and 5.1e1) were counted as different modes; the calculator now reduces every value to lowest terms first. In Chromium: the seven sample scores showed a mean of 85.714285714286…, median 88, mode 92 (2 times), range 25, sum 600 and both standard deviations; 0.1 and 0.2 summed to exactly 0.3; a pasted column with 51 and 5.1e1 showed mean 27 and modes 15 and 51; grades 90, 82, 75 weighted 0.5, 0.3, 0.2 gave 84.6; a missing weight and a word in the list showed messages; the page fitted a 390 px phone with no errors.
| Seven scores: 85, 92, 78, 92, 88, 95, 70 | Result |
|---|---|
| Mean | 85.714285714286… |
| Median | 88 |
| Mode | 92 |
| Range | 25 |
| Sample standard deviation | 8.920282… |
| Population standard deviation | 8.258576… |
Frequently Asked Questions
Built by Derek Giordano · Part of Ultimate Design Tools