Mathematics
Use this standard deviation calculator to calculate calculate population variance and standard deviation for three values.
Calculator
Choose what you want to calculate, enter realistic values, adjust units where shown, and use the scenario section for repeated-use planning.
This calculator applies the formula Standard deviation = sqrt(variance). Enter each value with the matching unit, and AZCalculate updates the result instantly.
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Projected
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Trust note
This calculator follows the shown formula and is intended for everyday reference, learning, and quick checks.
Standard deviation = sqrt(variance)
This calculator applies the formula Standard deviation = sqrt(variance). Enter each value with the matching unit, and AZCalculate updates the result instantly.
Assumptions
Avoid mistakes
Follow the reasoning, not only the final number.
Enter the known values in the calculator fields.
Starting with clearly defined values and units prevents the most common calculation errors.
Keep the units consistent with the labels shown beside each input.
This step transforms the known values into the form required by the formula.
Apply the formula: Standard deviation = sqrt(variance).
This step transforms the known values into the form required by the formula.
Review the primary result and supporting values.
Compare the result with your real-world goal, such as measure spread.
Worked example
Variance: 16.67; Standard deviation: 4.08
Calculator guide
Calculate population variance and standard deviation for three values. This page includes an interactive calculator, concise formula notes, worked examples, FAQs, related calculators, and practical guidance you can revisit whenever needed.
References
We work hard to keep every calculator accurate and useful. If you notice a calculation error, missing option, or unclear explanation, please let us know so we can review and correct it promptly.
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FAQ
It uses Standard deviation = sqrt(variance) and calculates the result from the values you enter.
Yes. AZCalculate calculator pages include copy, share, and print actions.
Steps help you see whether the formula, substitutions, and arithmetic all match the problem.
Use the calculator mode that matches the problem and keep values consistent.
Use it as an estimate and compare it with the formula, assumptions, and examples shown on the page.
Real-world inputs can include local rules, changing rates, measurement tolerances, and conditions outside the core formula.
Enter the known values requested by the calculator. Use the unit selectors where available and make sure the values describe the same scenario.
The calculator follows the formula shown on this page. Accuracy depends on the values, units, assumptions, and rounding used in your scenario.
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Continue with closely related tools selected from the same subject and matching calculation needs.
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