Online Standard Deviation Calculator
Calculate Population and Sample Standard Deviation. Processing takes place locally in your browser.
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What Online Standard Deviation Calculator does
Calculate Population and Sample Standard Deviation
Worked example
Input
2, 4, 4, 4, 5, 5, 7, 9
Result
Population SD 2; sample SD about 2.138
Calculation rule
Variance averages squared distances from the mean. Population variance divides by n; sample variance uses n−1 before taking the square root.
Practical uses
- Check a small calculation before applying the same rule to a longer list.
- Prepare normalized numeric data for a spreadsheet, report or test fixture.
- Compare the copied result with the displayed input count and options.
Limits and review checks
- Confirm decimal separators, signs, leading zeros and inclusive boundaries before relying on the output.
- Very large lists or exhaustive permutations can consume substantial browser memory.
- Floating-point decimals and rounded shares may differ by a final displayed unit; review the shown precision.
Frequently asked questions
Are my numbers uploaded?
No. This tool performs its normal parsing and calculation in your current browser.
Why can another calculator show a different result?
Check parsing rules, rounding precision, population versus sample settings, boundary inclusion and whether duplicate values are retained.
Processing takes place locally in your browser.