Variance is the average of the squared differences between each value and the mean, and it equals the standard deviation squared. Paste your numbers into the browser-based standard deviation calculator and it returns both the population and sample variance instantly, computed locally.
To find the variance, calculate the mean of your data, subtract it from every value, square each difference, and average those squared differences. Because the differences are squared, variance is expressed in squared units, which is why people usually take its square root to get the standard deviation back in the original units. Variance and standard deviation describe the same spread, just on different scales.
Population variance divides the sum of squared differences by the number of values, while sample variance divides by the number of values minus one. You use sample variance when your data is only a sample of a larger group. The calculator computes both, along with the mean and standard deviation, entirely in your browser so your data stays on your device.
Standard deviation is the square root of the variance, so squaring the standard deviation gives the variance back.
Squaring makes every difference positive and gives larger deviations more weight, which is the definition of variance.
No. The calculation happens in your browser and your data is never sent anywhere.