Results will appear here after you enter values.
FAQ
What is the difference between population and sample standard deviation?
Population standard deviation divides variance by N. Sample standard deviation uses N-1 to provide an unbiased estimate of population variability.
How should I format my data?
You can separate values with commas, spaces, or line breaks. Invalid entries trigger an error so you can fix them quickly.
How precise are the results?
The calculator shows up to six decimal places. Copy the results if you need additional formatting.
Should I use sample or population standard deviation?
Use sample standard deviation when your values are a subset used to estimate a larger population. Use population standard deviation when the list contains every value in the group you are describing.
How do outliers affect the result?
Outliers increase variance and standard deviation because squared deviations give large gaps more weight. Review the min and max before using the result in a report.
Do units change the standard deviation?
The standard deviation uses the same unit as the input values. Converting every value from meters to centimeters, for example, also scales the standard deviation by the same factor.
Why can another calculator show a slightly different value?
Different tools may round at different stages or default to population instead of sample variance. Compare the count, mean, variance formula, and displayed precision before treating the results as inconsistent.
How to use Mean & Standard Deviation Calculator effectively
What this calculator does
This page summarizes a numeric dataset by count, mean, variance, and standard deviation. It calculates both population and sample formulas so you can match the method to the data you actually have.
Input format
Paste values separated by commas, spaces, or line breaks. Keep units consistent before pasting; the calculator treats every accepted token as one numeric observation in the same dataset.
Sample vs population
Population variance divides by N and describes the exact list you entered. Sample variance divides by N-1 and is usually the better choice when your data is a sample used to estimate a wider population.
Variance and standard deviation
Variance reports the average squared distance from the mean. Standard deviation is the square root of variance, so it returns to the original unit and is usually easier to explain in reports.
Outliers and review
Check the smallest and largest values before interpreting spread. A single unusually high or low value can move variance and standard deviation much more than it moves the mean.
Rounding policy
Calculations use the parsed numeric values and round only for display. If another tool differs slightly, compare whether it used sample or population variance and whether it rounded intermediate values.