Enter a list of numbers to find the mean, median, mode, range, variance, and standard deviation.
These three measures of central tendency each describe the "center" of a data set differently. Mean is what most people think of as the average: add all numbers and divide by how many there are. Median is the middle number when values are sorted (or the average of the two middle numbers if the count is even). Mode is the value that appears most often.
Use the mean for symmetric data without extreme outliers (like test scores in a normal class). Use the median when data is skewed or has outliers (like household incomes, where a few billionaires would pull the mean way up). Use the mode for categorical data or when you need the most common value (like the most popular shoe size).
These measure how spread out the data is. Variance is the average of the squared differences from the mean. Standard deviation is the square root of variance, which puts the spread back into the same units as the data. This calculator shows both population (divide by N) and sample (divide by N-1) versions. Use population when you have all data points; use sample when working with a subset of a larger group.