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Standard Deviation Calculator

Calculate population and sample standard deviation, variance and mean.

Enter the values for the problem

Enter the numbers, equation values, scores, or dimensions requested by the standard deviation tool. Review the supporting outputs to check the result and understand the relationship between the values.

Important: Use the inputs that match your situation. Results are estimates based on the values and assumptions entered.
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Guidance

Enter the problem exactly

For standard deviation, copy signs, decimals, fractions, coefficients, units, or grade weights carefully. A small transcription error can produce a completely different result.

Use the supporting outputs to check your work

Do not stop at the highlighted answer. Review the intermediate or related values because they can reveal whether the setup matches the problem.

Keep the method with the answer

When using the result for classwork or practice, understand the relationship or formula shown by the tool so you can reproduce the process without the calculator.

Understand this calculator

How to use it

Start with the values requested by the Standard Deviation tool and replace any sample numbers with figures from your actual situation. Calculate population and sample standard deviation, variance and mean. Keep every entry in the unit and time period shown beside the field, then review the highlighted result together with the supporting outputs.

What the results mean

The highlighted result is the main answer produced by the Standard Deviation calculation. The additional result cards provide context, components, ratios, costs, quantities, or comparison values that help explain why the primary result changed when you adjusted an input.

How the calculation works

Standard deviation summarizes how far values typically spread from the mean. Population and sample calculations use different divisors, so choose the result that matches whether your list represents the full population or a sample.

Example and practical context

After calculating the answer, change one input to a simple value you can verify by hand. If the calculator behaves as expected on the simple case, return to the original problem and use the supporting outputs to check your setup.

Results are estimates based on the values and assumptions entered. Review the Methodology and Calculator Disclaimer for important limitations.