How to use the Standard Deviation Calculator
The standard deviation calculator helps you measure how spread out your data is from the average. Whether you are analyzing test scores, sales figures, or scientific measurements, standard deviation tells you how much values typically differ from the mean. This free tool computes the mean (average), variance (average of squared differences from the mean), and standard deviation (square root of variance) in one step. Enter your numbers separated by commas, spaces, or new lines, then click "Get statistics" to see the results.
Standard deviation is one of the most widely used statistics in education, business, and research. A low standard deviation means most values are close to the mean; a high one means they are more spread out. Variance is the same idea in squared units, which is useful in many formulas. This calculator uses the population formula: it divides by the number of values (n) when computing variance and standard deviation. That is appropriate when your data set includes every member of the group you care about, such as all students in a class or all sales in a month.
To get accurate results, enter only numeric values. The calculator ignores blank entries and non-numeric text. You can paste data from a spreadsheet or type values by hand. Results are rounded to four decimal places for readability. Use this tool for homework, quick data checks, or to compare the spread of different data sets. It works on phones and tablets as well as desktops, so you can run the numbers wherever you are.
Understanding standard deviation improves your ability to interpret charts, reports, and studies. Together with the mean, it gives you a clear picture of both the center and the spread of your data. Students, teachers, analysts, and anyone working with numbers can rely on this standard deviation calculator for fast, correct results without manual formulas.